A bookcase is to be constructed as shown in the figure below. The height of the bookcase is 4 feet longer than the length of a shelf. If 20 feet of lumber is available for the entire unit (including the shelves, but NOT the back of the bookcase), find the length and height of the unit

Answer 1

h = l + 4

Assume a box, but the two shelves will not necessarily be at the top and bottom of the box. Find the perimeter.

2h + 2l = 20

Substitute l + 4 for h in the second equation and solve for l. Put that value in the first equation to find h. Check by putting both values into the second equation.

Answer 2

find the ratio of whole numbers that is equivaletion to the radio of 16 ft to 10 yd.