Question

Construct abc in which ab =7cm ac=9.5cm and abc=120 degree measure bc

Answer 1

c = 7
b = 9.5
B = 120 deg
law of cosines
b^2 = a^2 + c*2 - 2 * a * c * cos B
9.5^2 = a^2 + 7*2 - 14 a * -0.5
90.25 = a^2 + 49 + 7 a
a^ + 7 a - 41.25 = 0
a = about 3.81 for positive root

Answer 2

4cm