math
posted by danica .
Find the area and perimeter of an isosceles triangle the base is 16.0 ft and one of the legs is 20.0 ft i don't know the height how would i do this?

half the base is 8
h^2 = 20^2  8^2 = 40064 = 336
h = √336 = 4√21
a = 1/2 bh = 1/2 (16)(4√21) = 32√21
p = 20+20+16 = 56