Answer:b = (2A - hB)/h
Explanation:
See , we know area of a trapezoid is equal to 1/2*(sum of parallel sides)* perpendicular distance between parallel sides.
Here B and b are parallel sides which we know by comparing the equation.
And 'h' here is the perpendicular distance between parallel sides.
We have to write the equation in terms of one of the parallel sides 'b'
Our formula is A = 1/2*h*(B+b)
I.e. 2A = h*(B+b) (Multiplying both sides by 2)
I.e. 2A - hB = hb
I.e. b = (2A - hB)/h
Hope it helps!!!