The vertex angle of an isosceles triangle is 42 more than 3 times the base angles. Find the vertex angle. a The vertex angle is 124.8°.

b The vertex angle is 27.6°.

c The vertex angle is 40.8°.

d The vertex angle is 82.8°.

a

Step-by-step explanation:

The sum of the 3 angles in a triangle = 180°

let x be the base angles, then vertex angle is 3x + 42

Sum the 3 angles and equate to 180, that is

x + x + 3x + 42 = 180

5x + 42 = 180 ( subtract 42 from both sides )

5x = 138 ( divide both sides by 5 )

x = 27.6

Thus

vertex angle = 3x + 42 = 3(27.6) + 42 = 82.8 + 42 = 124.8° → a

0.32

step-by-step explanation:

2.24/7

answer: x=60