Geometry math question

Question

Find the measure of each angle in Triangle ABC. a=50-x  b=9x-40  c=90

A)a=130  b= 60  c=90

B) a=60  b=130  c=90

C)  a=40  b=50  c=90

D)  a=50  b=40  c=90

 

 

Answer 1

a + b + c = 180

 

(50 - x) + (9x - 40) + 90 = 180

 

8x = 80

 

x = 10

 

a = 40

 

b = 50

 

answer C

Answer 2

The three angles in a triangle add up to 180^o; that is a + b + c = 180^o.  By inspection the answer cannot be A) or B) since the three angles sum to more than 180°.  That leaves C) and D) as the possible answers. 

 

a + b + c = 180

50-x + 9x-40 + 90 = 180

8x + 100 = 180

 

Solve for x.  Once you have x, a = 50-x, b= 9x-40, c = 90.