Make the given changes in the indicated examples of this section and then solve the given problems.

In Example 2, change the equilateral triangle of side 21 in. to a square of side 21 in. and then find the length of molding.

Data from Example 2 

An architect designs a room with a rectangular window 36 in. high and 21 in. wide, with another window above in the shape of an equilateral triangle, 21 in. on a side. See Fig. 2.54. How much molding is needed for these windows?

The length of molding is the sum of the perimeters of the windows. For the rectangular window, the opposite sides are equal, which means the perimeter is twice the length l plus twice the width w. For the equilateral triangle, the perimeter is three times the side s. Therefore, the length L of molding is

L = 21+ 2w + 3s 2(36) + 2(21) + 3(21) 177 in.