Question

∠C and ​ ∠D ​ are vertical angles with m∠C=−x+26 and m∠D=2x−10 . What is m∠D ? Enter your answer in the box.

Answer 1

-x+26=2x-10
+x +10 +x +10
36+3x
divde by 3
12=x

m∠D=2(12)-10
=24-10
=14

Answer 2

m∠D=14

Explanation:

∠C and ​ ∠D ​ are vertical angles with m∠C=−x+26 and m∠D=2x−10

Vertical angles are equal. So equate the angles C and d . Solve for x

m∠C=m∠D

`-x+26=2x-10`

Subtract 2x from both sides

`-3x+26=-10`

Subtract 26 from both sides

`-3x=-36`

Divide both sides by -3

x=12

m∠D=2x−10

Substitute 12 for x

m∠D=2(12)−10=24-10= 14