Accepted Answer
Two angles in the same parallelogram must either be equal or else add up to 180 degrees. These two are obviously not equal, so they must add up to 180.A + B = 180A = 180 - B (we'll use this in just a second)A = 3B + 40180 - B = 3B + 40Add 'B' to each side:180 = 4B + 40Subtract 40 from each side:140 = 4BDivide each side by 4 :35 = BA = 180 - B = 145
Accepted Answer
[tex]\alpha+\beta=180^o\\\\\alpha=3\beta+40^o\\\\substitute\\\\3\beta+40^o+\beta=180^o\\4\beta=180^o-40^o\\4\beta=140^o\ \ \ \ /:4\\\beta=35^o\\\\\alpha=3\cdot35^o+40^o=105^o+40^o=145^o\\\\Solutions:35^o\ and\ 145^o.[/tex]