Help, Please, will give 20 points and brainiliest. URGENT!
 
											 
											Answer:
Step-by-step explanation:
b = 21 is the base, a is the height
area = 0.5ab = 210
ab = 420
a = 420/b = 420/21 = 20 ft
length of hypotenuse = √(a²+b²) = √(20²+21²) = √841 = 29 ft