Find the length of the field first. To do this, write a formula for the perimeter, P, of the field: P = 210 ft = 2(45 ft) + 2L.
Then 2L = 210 - 90 = 120, and L = 60 (feet).
The area of the field is thus WL = (45 ft)(60 ft) = 2700 sq ft
Supplementary means they equal 180 when added. Therefore:
X+56+3x=180
Combine common units
4x+56=180
Subtract 56 from both sides
4x=124
Divide by 4
X=31
Now we know the smaller angle is 31 degrees. Now we plug that into the larger angle:
3(31)+56
93+56
149
The larger angle is 149 degrees.
I hope this Helps!
