Warm Up Solve. 1. x + 30 = x = x = = 61 + x 5. x + 20 = 90 Course Points, Lines, Planes, and Angles x = 60 x = 77 x = 148 x = 29 x = 70

Problem of the Day Mrs. Meyer’s class is having a pizza party. Half the class wants pepperoni on the pizza, of the class wants sausage on the pizza, and the rest want only cheese on the pizza. What fraction of Mrs. Meyer’s class wants just cheese on the pizza? Course Points, Lines, Planes, and Angles

Learn to classify and name figures. Course Points, Lines, Planes, and Angles TB P

Vocabulary pointlineplane segmentrayangle right angleacute angle obtuse anglecomplementary angles supplementary angles vertical angles congruent Insert Lesson Title Here Course Points, Lines, Planes, and Angles

Course Points, Lines, Planes, and Angles Points, lines, and planes are the building blocks of geometry. Segments, rays, and angles are defined in terms of these basic figures.

Course Points, Lines, Planes, and Angles A point names a location. A Point A

Course Points, Lines, Planes, and Angles A line is perfectly straight and extends forever in both directions. line l, or BC B C l

Course Points, Lines, Planes, and Angles A plane is a perfectly flat surface that extends forever in all directions. plane P, or plane DEF D E F P

Course Points, Lines, Planes, and Angles G H A segment, or line segment, is the part of a line between two points. GH

Course Points, Lines, Planes, and Angles K J A ray is a part of a line that starts at one point and extends forever in one direction. KJ

Course Points, Lines, Planes, and Angles Additional Example 1: Naming Points, Lines, Planes, Segments, and Rays A. Name 4 points in the figure. B. Name a line in the figure. Point J, point K, point L, and point M Any 2 points on a line can be used. KL or JK

Course Points, Lines, Planes, and Angles Additional Example 1: Naming Points, Lines, Planes, Segments, and Rays C. Name a plane in the figure. Plane, plane JKL Any 3 points in the plane that form a triangle can be used.

Course Points, Lines, Planes, and Angles Additional Example 1: Naming Points, Lines, Planes, Segments, and Rays D. Name four segments in the figure. E. Name four rays in the figure. KJ, KL, JK, LK JK, KL, LM, JM

Course Points, Lines, Planes, and Angles An angle () is formed by two rays with a common endpoint called the vertex (plural, vertices). Angles can be measured in degrees. One degree, or 1°, is of a circle. m1 means the measure of 1. The angle can be named XYZ, ZYX, 1, or Y. The vertex must be the middle letter X Y Z 1 m1 = 50°

Course Points, Lines, Planes, and Angles The measures of angles that fit together to form a straight line, such as FKG, GKH, and HKJ, add to 180°. F K J G H

Course Points, Lines, Planes, and Angles The measures of angles that fit together to form a complete circle, such as MRN, NRP, PRQ, and QRM, add to 360°. P R Q M N

Course Points, Lines, Planes, and Angles A right angle measures 90°. An acute angle measures less than 90°. An obtuse angle measures greater than 90° and less than 180°. Complementary angles have measures that add to 90°. Supplementary angles have measures that add to 180°.

Course Points, Lines, Planes, and Angles A right angle can be labeled with a small box at the vertex. Reading Math

Course Points, Lines, Planes, and Angles Additional Example 2: Classifying Angles A. Name a right angle in the figure. B. Name two acute angles in the figure. TQS TQP, RQS

Course Points, Lines, Planes, and Angles Additional Example 2: Classifying Angles C. Name two obtuse angles in the figure. SQP, RQT

Course Points, Lines, Planes, and Angles Additional Example 2: Classifying Angles D. Name a pair of complementary angles. TQP, RQS mTQP + mRQS = 47° + 43° = 90°

Course Points, Lines, Planes, and Angles Additional Example 2: Classifying Angles E. Name two pairs of supplementary angles. TQP, RQT SQP, SQR mTQP + mRQT = 47° + 133° = 180° mSQP + mSQR = 137° + 43° = 180°

Course Points, Lines, Planes, and Angles Congruent figures have the same size and shape. Segments that have the same length are congruent. Angles that have the same measure are congruent. The symbol for congruence is , which is read “is congruent to.” Intersecting lines form two pairs of vertical angles. Vertical angles are always congruent, as shown in the next example.

Course Points, Lines, Planes, and Angles Additional Example 3A: Finding the Measure of Vertical Angles In the figure, 1 and 3 are vertical angles, and 2 and 4 are vertical angles. If m1 = 37°, find m3. The measures of 1 and 2 are supplementary. The measures of 2 and 3 are supplementary. m2 = 180° – 37° = 143° m3 = 180° – 143° = 37° So m1 = m3 or m1 = m3. ~

Course Points, Lines, Planes, and Angles Additional Example 3B: Finding the Measure of Vertical Angles In the figure,  1 and  3 are vertical angles, and  2 and  4 are vertical angles. If m4 = y°, find m2. m  3 = 180° – y° m  2 = 180° – (180° – y°) = 180° – 180° + y° = y° Distributive Property m2 = m4 So m4 = m2 or m4  m2.

Course Points, Lines, Planes, and Angles Lesson Quiz In the figure, 1 and 3 are vertical angles, and 2 and 4 are vertical angles. 1. Name three points in the figure. 3. Name a right angle in the figure. 4. Name a pair of complementary angles. 5. If m1 = 47°, then find m3. 2. Name two lines in the figure. Possible answer: A, B, and C Possible answer: AGF Possible answer: 1 and 2 47° Possible answer: AD and BE