Question

In triangle ABC, angle A is equal to angle C, BA=x+20,CA=4x-30, and BC=3x+14. What is the length of BC?​

Answer 1

BC = 23

Explanation:

Since ∠ A = ∠ C then the triangle is isosceles with AB = BC, that is

3x + 14 = x + 20 ( subtract x from both sides )

2x + 14 = 20 ( subtract 14 from both sides )

2x = 6 ( divide both sides by 2 )

x = 3

Thus

BC = 3x + 14 = 3(3) + 14 = 9 + 14 = 23