Answer:
D) 3 cm
Explanation:
area = 1/2(b1 + b)(h)
91 = 1/2(10 + b)(14)
simplify:
91 = (5 + 1/2b)14 = 70 + 7b
subtract 70 from each side of the equation:
21 = 7b
b = 3
Area of trapezoid=91cm²
height[h]=14cm
one base[B]=10cm
another base[b]=b(let)
we have
½×h[B+b]=91cm²
½×14[10+b]=91
10+b=91/7
b=13-10
b=3
So another base's length is 3cm.
