Subtract the sum of the angles from 180 degrees to get the missing angle. For example if a triangle in a quadrilateral had the angles of 30 and 50 degrees, you would have a third angle equal to 100 degrees (180 - 80 = 100).
B: The width of the vegetable bed is 5 feet. The length is 13 feet.
The answer is b because 2S + L is equal to L + 2S.
Your equations would be 3x+1y=86 and x+y=42
the answer would be 22 field goals and 20 extra points.