Answer:
8 feet
Step-by-step explanation:
Given data
Area= 64 square feet
Base= x feet
Height= x+8 feet
The expression for the area
A= 1/2b*h
substitute
64= 1/2*x*(x+8)
64= 1/2*x^2+8x
64= (x^2+8x)/2
cross multiply
64*2= x^2+8x
128= x^2+8x
rearrange
x^2+8x-128= 0
using the quadratic formula
a=1
b=8
c=-128
x= -b±√b^2-4ac/2a
x= -1±√8^2-4*1*-128/2*1
simplifying
x= 8
x=-16
Hence the height of the base is
h= 8 feet
i really do not know the answer
The surface area is 88ft.
Just to let you know just in case if you have the same question is that the formula of finding the surface area of a rectangular prism is A = 2(wl + hl + hw)
the first one
2. 283
3. 50
4. 23
5. 221
7. -152