CK-12 Geometry - Second Edition

http://www.ck12.org Chapter 4. Triangles and Congruence

26.Given: Isosceles 4 ICSwith^6 Cand^6 SIOis the perpendicular bisector ofCSProve:IOis the angle bisector

of^6 CIS

27.Given: Isosceles 4 ABCwith base angles^6 Band^6 CIsosceles 4 XY Zwith base angles^6 Y and^6 Z^6 C∼=

(^6) Z,BC∼=Y ZProve: 4 ABC∼= 4 XY Z
Constructions

28. Using the construction of an equilateral triangle (investigation 4-6), construct a 30◦angle.Hint: recall how to
    bisect an angle from investigation 1-4.


29. Use the construction of a 60◦angle to construct a 120◦angle.


30. Is there another way to construction a 120◦angle? Describe the method.


31. Describe how you could construct a 45◦angle (there is more than one possible way).

Review Queue Answers

1.( 5 x− 1 )◦+( 8 x+ 5 )◦+( 4 x+ 6 )◦= 180 ◦

17 x+ 10 = 180 ◦

17 x= 170 ◦

x= 10 ◦

2.( 2 x− 4 )◦+( 3 x− 4 )◦+( 3 x− 4 )◦= 180 ◦

8 x− 12 = 180 ◦

8 x= 192 ◦

x= 24 ◦

3.x− 3 = 8

x= 5

4. Each angle is^180
   ◦
   3 , or 60

◦