Know that quadrilaterals’ with 4 sides the degrees should all add up to 360
a. 110
(110+62+78= 250
360 - 250 = 110)
b. 66
(84+78+2b+b = 360
162+3b = 360
3b = 198
b = 66)
c. 83
For 5 sides the degrees should add up to 540)
(101+152+38+2c+c = 540
291+3c=540
3c = 249
c = 83)
d. 30
For 6 sides the degrees should add up to 720
(108+102+4d+4d+4d+5d = 720
210+17d= 720
17d = 510
d = 30)
As for the others I’ll label them 1, 2, and 3...
1. 60
(105+75+2b+b = 360
180+3b= 360
3b = 180
b = 60)
2. 78
(125+65+92+a = 360
282+a = 360
a = 78)
3. 80
(130+65+120+[2c-15]+c = 540
315+[2c-15]+c = 540
3c-15 = 225
3c = 240
c = 80
