2220c And 2220d Are Vertical Angles With M2220c=22122x+90 And M2220d=X221230 . What Is M2220d ? Enter Your Answer In The Box.

∠C and ∠D are vertical angles with m∠C=−2x+90 and m∠D=x−30 . What is m∠D ? Enter your answer in the box.

 

Answer:

m<D = 10°

Step-by-step explanation:

Vertical angles have the same measure

If <C is equal to - 2x+90 and <D is x-30

Our equation will be

-2x+90 = x - 30

120=3x

x = 40

Then substitute

<C=-2x+90

= -2(40) + 90

= -80 + 90

<C = 10

<D= x-30

= 40-30

<D=10

Both of them have the same measure so it is correct