Using the Sine Rule:-
20 /sin 45 = BC / sin 30
BC = 20 sin 30 / sin45
= 20 * 1/2 / 1 / sqrt2
= 20 * 1/2 * sqrt2
= 10 sqrt2 answer
If the diameter is 30 ft then the area of the circle is 706.5 you can approximate it if you want and you will have 707.
Answer:
The answer is (5.)2,800.00
X = -33 + 42
x = 42 - 33
x = 9