Question

What is the measure of angle A in this triangle?

Answer 1

The Answer is 40°

Explanation:

Base angles of an isosceles triangle are equal

x+30=70

x=70-30

x=40°

so,

<C=70°

<A+<B+<C=180°

let <A be X

X+70+70=180°

X+140=180°

X=180-140

X=40°

X=2x-10

40°=2x-10

2x=40+10

2x=50°

divide both sides by 2

x=25°