Answer:
D=121
Explanation:
First fin the angles on the inside using the outer angles. Always use 180 as your main number to subtract from. 180-131 = 49 180-108= 72 72+49=121
180-121=59 180-59=121
Or an easier way is to see if your outer angles equal up to 360
So 131+108=239
360-239=121
And there's your solution.