Question

∠C and ​ ∠D ​ are vertical angles with m∠C=−2x+90 and m∠D=x−30

Answer 1

-2x+90 = x-30

2x+x = 90+30

3x = 120

x = 120/3

x = 40

Now, m∠D = x-30 = 40-30 = 10

Not sure if this is what your looking for but their magnitudes would be equal

Step-by-step explanation: