Answer:
14°
Step-by-step explanation:
To find m∠D, the value of x must be known. Because ∠C and ∠D are vertical angles, we can use the equation -x + 26=2x - 10 to find the value of x. After solving the equation, we find that x = 12, so by plugging in the value of x into the original expression, it is shown that m∠D = 14°.
