Question

If ∠C and ∠D are vertical angles and m ∠ C = x + 5 and m ∠ D = –2x + 80, what is m ∠ C?

Answer 1

m∠C=30°

Explanation:

we know that

Vertical Angles are the angles opposite each other when two lines cross. They are always equal

so

m∠C=m∠D

substitute the given values

`(x+5)\°=(-2x+80)\°`

Solve for x

`x+2x=80-5\\3x=75\\x=25`

Find the measure of angle C

m∠C=(x+5)°

substitute the value of x

m∠C=(25+5)=30°