Answer:
25 = base
Explanation:
I searched all of this on YT to try and help
so first we need to know the area of a Trapezoid
A = 1/2h(b + b)
86 = 1/2(18 + b)4
we dont know the base where going to put b
we also dont like fractions so where going to get rid of 2 by multiplying 2 by 2. And we do it in both ends, so where doing the same with our Area.
172 = (18 + b)4
the 4 is multipling so divide it on both ends.
43 = (18 + b)
then do the opposite operation on the 18, by subtracting 18 on both sides.
25 = b
is the base
check the work by plugging it back in
A = 1/2h(b + b)
A = 1/2 4(18+25)
A = 1/2 4(43)
A = 1/2(172)
A = 86in