Answer Key Math 302B, Section 1 Part 1: Define each term, and then draw a picture then represents each definition. Note: All of the following definitions are not to be taken as precise definitions. Pictures are not included. 1. Point 2. Collinear Points 3. Coplanar points 4. Line A reference to a location. Points that lie on the same line. Points that lie on the same plane. An infinite collection of points that indicate a straight path. 5. Line Segment 6. Concurrent Lines 7. Perpendicular Lines 8. Skew Lines A subset of a line. This subset consists of two endpoints and all of the points in between those endpoints. 9. Ray Three of more lines intersecting at a single point. Refer to discussion in class. Two lines that don’t intersect because they don’t lie in the same plane. 10. Angle 11. Exterior of an angle 12. Interior of an angle A subset of a line that contains a specific point (endpoint) and all of the points on the same side. 13. Acute angle The union of two rays that have a common endpoint. A portion of an angle that The intersection of the exists space disjoint from the rays that create the angle. 14. Obtuse angle 15. Straight angle 16 Reflex angle An angle that measures less than 90 degrees. An angle that measures between 90 and 180 degrees. An angle that measures exactly 180 degrees. An angle whose measure is greater than 180 degrees. 17. Complementary angles 18. Supplementary angles 19. Vertical angles 20. Right angle Two angles whose measures sum up to 90 degrees. Two angles whose measures sum up to 180 degrees. Angles that are “opposite” each other (in regards to location) when two lines intersect. An angle whose measure is exactly 90 degrees. 21. Plane 22. Parallel Lines An unbounded 2dimensional shape. A surface that contains at least three points not all in a straight line and is such that a line drawn through any 2 points in it lies wholly in the surface. Co-planar lines that never intersect. (Note: I am only defining parallel lines for co-planar lines) Part 2: Name each figure. 1. 2. S G E M line GM line segment MG Ray GM Ray MG line SE line segment ES Ray SE Ray ES Part 3: Complete. 1. 2. Name a pair of adjacent angles. Name a pair of complementary angles. Angle TMY and Angle YMN 4. 3. Angle ZMF and Angle FML 5. Name a pair of vertical angles. Angle QFC and Angle LFC 6. Name a pair of complementary angles. Angle GTZ and Angle ZTB Angle QGB and Angle EGH Name a pair of supplementary angles. Name a pair of supplementary angles. Angle LFH and Angle HFP Part 4: Answer each question. 1. 2. 3. NA GX QL KF AED and VDN are vertical angles. KZH and GZF are vertical angles. 4. HJ ED 5. ZUJ and HUR are vertical angles. 6. F G I C D A B H E Using a protractor, determine the measure of angle ABC. about 126° Angle Measure Using a protractor, determine the measure of angle DEF. about 51° Angle Measure Using a protractor, determine the measure of angle GHI. about 285° Angle Measure Part 5: Complete using the diagram provided. A 1 3 B F 2 G 4 E C D 1. Name the line marked 3 in six different ways. (all notations should have a double arrow over the letters): AC, CA, AB, BA, CB, BC 2. Name the line segment named 2 in two different ways. (all notations should have a straight line over the letters): BG, GB 3. Name the angle marked 1 in four different ways. < CAE, < BAE, < BAF, < EAC (there are different ways to name the angles than just what is listed here) 4. What is vertex marked 4? G (note a vertex is just a point, so I was only looking for you to name a point) 5. Name the ray beginning at F and going towards A. (the ray should have a single arrow over the letters): FA 6. Is DE = DC ? Explain. NO. They are going in different directions and as such, contain different points. One ray contains the point C, while the other does not. 7. Is BG = BE ? Explain. YES. Although they use a different second letter, they both start at B and go in the same direction. Therefore, they contain the same points. 8. Is BC = CB ? Explain. NO. One has the endpoint of B and the other has an endpoint of C. One ray contains the point A, while the other ray does not. 9. Name the sides of AFD. (Note: The sides of the angle are rays and should have single arrows over the letters.) FA and FD . Part 6: Complete. 1. Sketch four lines such that three are concurrent with each other and two are parallel to each other. 2. True or False? Briefly justify your answer a. If a line is perpendicular to a plane, then it is perpendicular to all lines in that plane. TRUE. Refer to discussion in class. b. If three lines are concurrent, then they are also coplanar. FALSE. Refer to discussion in class. 3. Sketch a pair of angles whose intersection is a. Exactly two points or explain why this is not possible. b. Exactly four points or explain why this is not possible