Question

What is the measurement of ABC ​

Answer 1

m<ABC=40

Explanation:

Ok so we need to break up this problem.

m<ABC=4x

m<BCA=7x-20

m<A= 90 degrees (We are given a right angle here)

Because of the Triangle Sun Theorem, all the angles here would add up to 180 degrees. So..

4x+7x-20+90=180

Solve

x=10

Then we look back and see that m<ABC is 4x

We plug in x

4(10)=m<ABC

m<ABC=40