Answer:
x = 36 , 2x = 72 , 3x = 108 , 4x = 144
Step-by-step explanation:
2x = P+Q (ΔABC, exterior angle property)
4x = R+S (ΔDBC, exterior angle property)
4x + 2x = P+Q+R+S = (P+R) + (Q+S) = (180 - 3x) + (180 -x) (supplementary)
6x = 360 - 4x
10x = 360
x = 36
2x = 72
3x = 108
4x = 144
check: sum of interior angles = (180 x 4) - (36+72+108+144) = 360
