Pre-AP Bellwork 6) Claire draws an angle that measures 56. Justin draws a congruent angle. Justin says his angle is obtuse. Is he correct? Why or why not?
Pre-AP Bellwork 7) ∠ MLN and ∠ JLK are complementary, m ∠ MLN = 7x − 1, and m ∠ JLK = 4x + 3. a. Solve for x. b. Find m ∠ MLN and m ∠ JKL. c. Show how you can check your answer.
Pre-AP Bellwork 8)Describe all the situations in which the following statements are true. a. Two vertical angles are also complementary. b. A linear pair is also supplementary. c. Two supplementary angles are also a linear pair. d. Two vertical angles are also a linear pair.
Pre-AP Bellwork Find the measure of each angle in the angle pair described. 9) The measure of one angle is 5 times the measure of its complement. 10) The measure of an angle is 30 less than twice its supplement.
1-5 Exploring Angle Pairs
Adjacent angles- two coplanar angles with a common side, a common vertex, and no common interior points
Which angles are adjacent? 1& 2, 2& 3, 3& 4, 4& 1 Vertical Angles – 2 angles that share a common vertex & whose sides form 2 pairs of opposite rays. 1& 3, 2& 4 Then what do we call 1& 3?
Linear Pair (of angles) 2 adjacent angles whose non-common sides are opposite rays. 1 2
Example Vertical angles? 1 & 4 Adjacent angles? 1& 2, 2& 3, 3& 4, 4& 5, 5& 1 Linear pair? 5& 4, 1& 5 Adjacent angles not a linear pair? 1& 2, 2& 3, 3&
Important Facts Vertical Angles are congruent. The sum of the measures of the angles in a linear pair is 180 o.
Example: If m 5=130 o, find m 3 m 6 m = 130 o =50 o
Example: Find x,y m ABE m ABD m DBC m EBC 3x+5 o y+20 o x+15 o 4y-15 o x=40 y=35 m ABE=125 o m ABD=55 o m DBC=125 o m EBC=55 o A B C D E
Complementary Angles 2 angles whose sum is 90 o o A 55 o B 1 & 2 are complementary A & B are complementary
Supplementary Angles 2 angles whose sum is 180 o o 50 o X Y 1 & 2 are supplementary. X & Y are supplementary.
Ex: A & B are supplementary. m A is 5 times m B. Find m A & m B. m A + m B = 180 o m A = 5(m B) Now substitute! 5(m B) + m B = 180 o 6(m B)=180 o m B=30 o m A=150 o