In the staircase-shaped region below, all angles that look like right angles are right angles, and each of the eight congruent sides marked with a tick mark have length 1 foot. If the region has area 53 square feet, what is the number of feet in the perimeter of the region?
Let's call the second longest side x .
Now we can see that the figure is a rectangle with 10 square feet removed from it. So...
area = (9 ft)(x ft) - 10 ft2
area = 9x ft2 - 10 ft2
53 ft2 = 9x ft2 - 10 ft2
53 = 9x - 10
63 = 9x
x = 7
And the perimeter, in feet = 9 + 7 + 9 + 7 = 32
Let's call the second longest side x .
Now we can see that the figure is a rectangle with 10 square feet removed from it. So...
area = (9 ft)(x ft) - 10 ft2
area = 9x ft2 - 10 ft2
53 ft2 = 9x ft2 - 10 ft2
53 = 9x - 10
63 = 9x
x = 7
And the perimeter, in feet = 9 + 7 + 9 + 7 = 32