Question

The length of one base of a trapezoid is 19 less than five times the length of the other base. If the trapezoid has a height of 18 feet an area of 477ft, find the length of the longer base

Answer 1

The length of the longer base is 41 ft.

Explanation

Lets assume, length of one base is $x$ ft.

As, another base is 19 less than five times the length of this base, so the length of another base $= (5x- 19) ft.$

The trapezoid has a height of 18 ft and area of 477 ft²

Formula for Area of trapezoid, $A=\frac{1}{2} (a+b)*h$ , where $a, b$ = Two bases of trapezoid and $h$ = height of the trapezoid.

Given in the question: $A= 477$ and $h= 18$

We have also two bases as: $a= x$ and $b= 5x-19$

So, according to the above formula...

$A= \frac{1}{2}(a+b)h\\\\ 477=\frac{1}{2}(x+5x-19)*18\\\\ 477=9(6x-19)\\\\477= 54x-171\\\\477+171=54x\\\\648=54x\\\\x=\frac{648}{54} = 12$

So, length of one base is $12 ft$  and another base $=(5*12-19)ft =(60-19)ft = 41 ft$

That means, the length of the longer base is 41 ft.