# Section 1.1 - Nets and Drawings for Visualizing Geometry Section 1.1 Nets and Drawings for Visualizing Geometry Students will be able to: make nets and drawings of threedimensional figures. Key Vocabulary: net isometric drawing orthographic drawing

Section 1.1 Nets and Drawings for Visualizing Geometry Section 1.1 Nets and Drawings for Visualizing Geometry In the Solve It, you had to see the projection of one side of an object onto a flat surface.

Visualizing figures is a key skill that you will develop in geometry. Section 1.1 Nets and Drawings for Visualizing Geometry You can represent a three dimensional object with a two-dimensional figure using special drawing techniques.

A NET is a two-dimensional diagram that you can fold to form a three-dimensional figure. A net shows all of the surfaces of a figure in one view. Section 1.1 Nets and Drawings for Visualizing Geometry Problem 1:

The net at the right folds into the cube shown beside it. Which letters will be on the top and front of the cube? How can you see the 3-D figure? Visualize folding the net at the seams so that the edges join together. Track the letter positions by

seeing one surface move in relation to another. Section 1.1 Nets and Drawings for Visualizing Geometry Problem 1: How can you determine by looking at the net that surface E and surface F will be opposite one another in the cube?

If the cube were turned one quarter-turn counterclockwise without lifting the bottom surface, which surface would be at the front of the cube? Section 1.1 Nets and Drawings for Visualizing Geometry Problem 2: What is the net for the graham cracker box to

the right? Label the net with its dimensions. Section 1.1 Nets and Drawings for Visualizing Geometry Problem 2: What is a net for the figure at the right? Label the net with its dimensions.

Is there another possible net for the figure? Section 1.1 Nets and Drawings for Visualizing Geometry An ISOMETRIC DRAWING shows a corner view of a three dimensional figure. It allows you to see the top, front, and side of the figure. You can draw an

isometric drawing on isometric dot paper. The simple drawing of a file cabinet at the right is an isometric drawing. A net shows a 3-D figure as a folded out flat surface. An isometric drawing shows a 3-D figure using slanted lines to represent depth.

Section 1.1 Nets and Drawings for Visualizing Geometry Problem 3: What is an isometric drawing of the cube structure at the right? Section 1.1 Nets and Drawings for Visualizing Geometry

Problem 3: What is an isometric drawing of the cube structure at the right? Section 1.1 Nets and Drawings for Visualizing Geometry An orthographic drawing is another way to represent a 3-D figure. An orthographic drawing

shows three separate views, a top view, a front view, and a right-side view. Although an orthographic drawing may take more time to analyze, it provides unique information about the shape of a structure. Section 1.1 Nets and Drawings for Visualizing Geometry

Problem 4: What is the orthographic drawing for the isometric drawing at the right? Solid lines show visible edges. Dashed lines show hidden edges.

An isometric drawing shows the same three views. Section 1.1 Nets and Drawings for Visualizing Geometry Problem 4:

What is the orthographic drawing for the isometric drawing at the right? Section 1.1 Nets and Drawings for Visualizing Geometry Section 1.1 Nets and Drawings for Visualizing Geometry

Section 1.2 Points, Lines, and Planes Students will be able to: Understand basic terms and postulates of geometry.

Key Vocabulary point coplanar opposite rays line

plane Collinear points space segment ray postulate

axiom intersection Section 1.2 Points, Lines, and Planes Section 1.2 Points, Lines, and Planes

Geometry is a mathematical system built on accepted facts, basic terms, and definitions. In geometry, some words such as point, line, and plane are undefined. Undefined terms are the basic ideas that you can use to build the definitions of all other figures in geometry. Although you can not define undefined terms, it is important to have a general description of

their meanings. Section 1.2 Points, Lines, and Planes Section 1.2 Points, Lines, and Planes Points that lie on the same line are collinear

points. Points and lines that lie in the same plane are coplanar. All the points of a line are coplanar. Section 1.2 Points, Lines, and Planes Problem 1:

suu r What are two other ways to name QT ? What are two other ways to name plane P? What are the names of thee collinear points? What are the names of four coplanar points?

Section 1.2 Points, Lines, and Planes The terms point, line, and plane are not defined because their definitions would require terms that also need defining. You can, however, used undefined terms to define other terms.

A geometric figure is a set of points. Space is the set of all points in three dimensions. Section 1.2 Points, Lines, and Planes Section 1.2 Points, Lines, and

Planes Problem 2: What are the names of the segments in the figure at the right? What are the names of the rays in the figure? Which of the rays in part (b) are opposite rays? Ray EF and Ray FE form a line. Are they opposite rays?

Section 1.2 Points, Lines, and Planes Problem 2: Do the names DE and ED represent different segments? Can the three points shown on the line be used to name a plane?

How are segments DE , EF , and DF related to each other? Section 1.2 Points, Lines, and Planes A postulate or axiom is an accepted statement of fact. Postulates, like undefined terms, are basic building

blocks of the logical system of geometry. You will use logical reasoning to prove general concepts in this book. Section 1.2 Points, Lines, and Planes You used Postulate 1-1 when you graphed equations

such as y = 2x + 8. You graphed two points and drew a line through the two points. Section 1.2 Points, Lines, and Planes When you have two or more geometric figures, their intersection is the set of points the figures have in common.

In algebra, one way to solve a system of two equations is to graph them like on the right. This uses Postulate 1-2. Section 1.2 Points, Lines, and Planes Section 1.2 Points, Lines, and

Planes Problem 3: Each surface of the box at the right represents part of a plane. What is the intersection of plane ADC and plane BFG? What are the names of the to planes that suu

r intersect at BF ? Section 1.2 Points, Lines, and Planes Problem 4: What plane contains points N, P, and Q? Shade the plane.

What plane contains points J, M, and Q? Shade the plane. What planes contains points L, M, and N? Shade the plane. Section 1.2 Points, Lines, and Planes Lesson Check

Section 1.2 Points, Lines, and Planes Lesson Check Section 1.3 Measuring Segments

Students will be able to: find and compare lengths of segments Key Vocabulary coordinate distance congruent segments midpoint

S=segment bisector Section 1.3 Measuring Segments The distance between points A and B is the absolute value of the difference of their coordinates, or |a b|. This value is also AB, or the length between A and B.

Section 1.3 Measuring Segments Problem 1: What is ST? What is UV? What is SV?

Section 1.3 Measuring Segments Section 1.3 Measuring Segments Problem 2: If EG = 59, what are EF and FG? What algebraic expression represents EG?

What is the numeric value given for EG? How should you check to make sure that the segment lengths are correct? Section 1.3 Measuring Segments When numerical expressions have the same value, you say that they are equal (=). Similarly, if two segments have the same length, then

the segments are congruent segments. The symbol for congruent is ____________. Section 1.3 Measuring Segments This means if AB = CD, then AB CD. You can also say that if AB CD, then AB = CD.

Section 1.3 Measuring Segments Problem 3: Are AC and BD congruent? Is Segment AB congruent to Segment DE? Section 1.3 Measuring Segments The midpoint of a segment is a point that divides the

segment into two congruent segments. A point, line, ray, or other segment that intersects a segment at its midpoint is said to bisect the segment. That point, line, ray, or segment is called a segment bisector. Section 1.3 Measuring Segments Problem 4: Q is the midpoint of PR .

What are PQ, QR, and PR? Section 1.3 Measuring Segments Problem 4(b): U is the midpoint of TV . What are TU, UV, and TV? Section 1.3 Measuring Segments

Lesson Check Section 1.3 Measuring Segments Lesson Check Section 1.4 Measuring Angles

Students will be able to: find and compare measures of angles Key Vocabulary angle sides of an angle vertex of an angle measure of an angle acute angle

right angle obtuse angle straight angle congruent angles Section 1.4 Measuring Angles

When you name angles using three points, the vertex MUST go in the middle. Section 1.4 Measuring Angles The interior of an angle is the region containing all of the points between the two sides of the angle. The exterior of an angle is the region containing all of the points outside of the angle.

Section 1.4 Measuring Angles Problem 1: What are the two other names for <1? What are the two other names for

Explain!! Section 1.4 Measuring Angles One way to measure the size of an angle is in degrees. To indicate the measure of an angle, write a lowercase m in front of the angle symbol. In the diagram, the measure of

Section 1.4 Measuring Angles The Protractor Postulate allows you to find the measure of an angle. Section 1.4 Measuring Angles The measure of

OC and Ray OD. Section 1.4 Measuring Angles Classifying Angles: You tell me: ACUTE OBTUSE

RIGHT STRAIGHT Section 1.4 Measuring Angles Problem 2: What are the measures of

congruent angles, each set is marked with the same number of arcs. Section 1.4 Measuring Angles Problem 3: Synchronized swimmers form angles with their bodies, as show in the photo. If m

Section 1.4 Measuring Angles Section 1.4 Measuring Angles Problem 4: If m

Students will be able to: identify special angle pairs and use their relationships to find angle measures Key Vocabulary

adjacent angles complementary angles linear pair vertical angles supplementary angles angle bisector

Section 1.5 Exploring Angle Pairs Special angle pairs can help you identify geometric relationships. You can use these angle pairs to find angle measures. Section 1.5 Exploring Angle Pairs Problem 1: Use the diagram at the right. Is the statement true?

Explain a.

c.

Explain a.

c.

diagram? Section 1.5 Exploring Angle Pairs Problem 2b: Can you make each conclusion from the information in the diagram? Explain. a. b.

c. d. Segment TW is congruent to Segment WV Segment PW is congruent to Segment WQ

Section 1.5 Exploring Angle Pairs A linear pair is a pair of adjacent angles whose noncommon sides are opposite rays. The angles of a linear pair form a straight angle. Section 1.5 Exploring Angle Pairs Problem 3:

vertex. Within the ray, a segment with the same endpoint is also an angle bisector. The ray or segment bisects the angle. In the diagram, Ray AY is the angle bisector of

Ray AC bisects

Section 1.7 Midpoint and Distance in the Coordinate Plane Students will be able to: find the midpoint of a segment find the distance between two points in the coordinate plane

Section 1.7 Midpoint and Distance in the Coordinate Plane What do you think we mean by the word midpoint? Ideas on how to find it on a number line? Ideas on how to find it on a coordinate plane?

Section 1.7 Midpoint and Distance in the Coordinate Plane You can use formulas to find the midpoint and length of any segment in the coordinate plane. Section 1.7 Midpoint and Distance in the Coordinate Plane Problem 1:

Segment AB has endpoints at -4 and 9. What is the coordinate of its midpoint? Segment JK has endpoints at -12 and 4 on a number line. What is the coordinate of its midpoint? Section 1.7 Midpoint and Distance

in the Coordinate Plane Problem 1b: Segment EF has endpoints E(7, 5) and F(2, -4). What are the coordinates of its midpoint M? Segment RS has endpoints at R(5, -10) and S(3, 6). What are the coordinates of its

midpoint M? Section 1.7 Midpoint and Distance in the Coordinate Plane Problem 2: The midpoint of Segment CD is M(2, -1). One endpoint is C(-5, 7). What are the coordinates of the other endpoint D?

The midpoint of Segment AB is M(4, -9). One endpoint is A(-3, -5). What are the coordinates of the other endpoint B? Section 1.7 Midpoint and Distance in the Coordinate Plane To find the distance between any two points in a coordinate

plane, you can use the Distance Formula. Do you remember any other way to find the distance between to coordinate points in a plane? Section 1.7 Midpoint and Distance in the Coordinate Plane Problem 3:

What is the distance between U(-7, 5) and V(4, -3)? Round to the nearest tenth. Section 1.7 Midpoint and Distance in the Coordinate Plane Problem 3: Segment SR has endpoints S(-2, 14) and R(3, -1). What is SR to the nearest tenth?

Section 1.7 Midpoint and Distance in the Coordinate Plane Lesson Check Section 1.7 Midpoint and Distance in the Coordinate Plane Lesson Check

Classifying Polygons In geometry, a figure that lies in a plane is called a plane figure. A polygon is a closed plane figure formed by three or more segments. Each segment intersects exactly two other segments at their endpoints. No two segments with a a common

endpoint or collinear. Each segment is called a side. Each endpoint is called a vertex. Classifying Polygons Classifying Polygons To name a polygon, start at any vertex and list the vertices consecutively in a

clockwise or counterclockwise direction. Two names for this polygon are DHKMGB and MKHDBG. Classifying Polygons You can classify a polygon by its number of

sides. The tables below show the names of some common polygons. Classifying Polygons You can also classify a polygon as concave or convex, using the diagonals of the polygon. A diagonal is a segment that connects two NONconsecutive vertices.

A Convex polygon has no diagonal with points outside of the polygon A Concave polygon has at least one diagonal with points

outside of the polygon Section 1.8 Perimeter, Circumference, and Area Problem 2: What is the circumference of the circle in terms of pi? What is the circumference

of the circle to the nearest tenth? a. b. Section 1.8 Perimeter, Circumference, and Area Problem 3: What is the perimeter of Triangle EFG?

Section 1.8 Perimeter, Circumference, and Area Problem 4: You want to make a rectangular banner similar to the one at the right. The banner shown is 2.5 feet wide and 5 feet high. To the nearest square yard, how much material do you need?

Section 1.8 Perimeter, Circumference, and Area Problem 4: You are designing a poster that will be 3 yard wide and 8 feet high. How much paper do you need to make the poster. Give your answer in square feet.

Section 1.8 Perimeter, Circumference, and Area Problem 5: What is the area of Circle K in terms of pi? Then round your answer to the nearest hundredth.

Section 1.8 Perimeter, Circumference, and Area Problem 6: What is the area of the figure at the right? Section 1.8 Perimeter, Circumference, and Area Problem 6:

What is the area of the figure at the right? Section 1.8 Perimeter, Circumference, and Area Lesson Check Section 1.8 Perimeter, Circumference, and Area

Lesson Check