perimeter of a trapezoid is 29 inches.?

Question

perimeter of a trapezoid is 29 inches. its nonparallel are 4 inches and 5 inches long. if the height of the trapezoid is 3 inches find its area

Answer 1

The area of a trapezoid is one half its height times the sum of the lengths of its parallel sides:

1/2 * h * (b1 + b2)

(You may know it as the height times the AVERAGE of the parallel sides, but that's the same equation with the "1/2" moved: h * (b1 + b2)/2.)

In this case, you know the perimeter (29 inches) AND the other two sides (4 and 5 inches). This means that the sum of the two parallel sides must be the remainder of the perimeter: 29 - (4+5) = 20 inches.

Since you have the sum of the two parallel sides, and the height, you have everything you need to calculate the area:

a = 1/2 * h * (b1 + b2)
a = 1/2 * 3 * 20
a = 30 square inches

Answer 2

P=29=4+9+x
x=20, with x being the sum of the two parallel sides, or the base sides

a=(1/2)h(b1+b2)

a=(1/2)(3)(20)
a= 30 in²