Question

In triangle ABC, angle A = 2x + 5, angle B = 4x + 10 and angle C = x - 31. Find the value of x.

Answer 1

x = 28°

Explanation:

Sum of a triangle is equal to 180°. Firstly you need to form an equation. Add all the angles which equals to 180°.

2x + 5 + 4x + 10 + x - 31 = 180°

Now simply and find the value of x. Add all the x terms and whole numbers.

7x + 5 + 10 - 31 = 180°

7x + 15 - 31 = 180°

7x - 16 = 180°

7x = 180° + 16

7x = 196

x = 196 ÷ 7

x = 28°

So the angles are:

Angle A = 2x + 5

2 x 28 + 5 = 61°

Angle B = 4x + 10

4 x 28 + 10 = 122°

Angle C = x - 31

28 - 31 = -3°

Answer 2

x=28

Explanation:

sum of all angles im a triangle = 180°

(2x+5) + (4x+10) + (x-31) = 180

7x=196

x=28