A ferris wheel
A construction worker whose making a ferris wheel would need to know and measure the circumference.
A theme park manger would need to find the circumference to know if the ferris wheel is too big to go into the park.
Hope that helps!!
Area= a*height
the formula for an isosceles trapezoid is 1/2(base1+base2)*height. 1/2 base 2 and 2a will simplify to a base length of a. a times height or a*height