Question

For a trapezoid, the following formula relates the area a, the two bases a and b, and the height h. a= g (a

Answer 1

A - area of a trapezoid;
a, b - two bases.
A = h * ( a + b ) / 2            / * 2  ( we have to multiply both sides by 2 )
2 A = h *( a + b )
2 A = h a + h b
h b = 2 A - h a
b = ( 2 A - h a ) / h
b = 2 A/h - a
Answer: D )