Answer:
80°
Step-by-step explanation:
The opposite angles of an inscribed quadrilateral add up to 180.
(2x + 13) + (3x + 37) = 180
(2x + 3y) + (5y) = 180
Solving the first equation:
5x + 50 = 180
5x = 130
x = 26
Solving the second equation:
2x + 8y = 180
2(26) + 8y = 180
52 + 8y = 180
8y = 128
y = 16
5y = 80. So ∠D = 80°.
