Question 358992
1.) A garden plot is to contain 240 sq.ft. If its length is to be three times its width, what should its dimensions be?
{{{A = (3w)*w = 3w^2 = 240}}},
{{{w^2 = 80}}}, {{{w = 4sqrt(5)}}}ft. Then {{{l = 12sqrt(5)}}}ft.


2.) The vertical end of trough,which is in the form of a trapezoid, has the following dimensions: width at the top is 1.65m, width at the bottom is 1.15m, and depth is 1.35m. Find the area of this section of the trough.
The vertical end of the trough is a trapezoid, and its area is given by
{{{A = (h/2)*(a+b)}}}.  Then area is {{{A = (1.35/2)*(1.65+1.15)}}}.
{{{A = 1.89}}}square meters.

3.) A metal washer 1 1/2 inches in diameter is pierced by a 3/4-inch hole. What is the area of the cross section of the washer? 
Area of the cross-section is {{{pi*(3/4)^2 - pi*(3/8)^2 = (27/64)*pi}}}square inches.