What is the perimeter of the walkway around the pool?

• A. 80 feet
• B. 88 feet
• C. 92 feet
• D. 96 feet

Answer: (B)

Think of the walkway as adding a uniform border around the pool. The outer edge you measure is the pool plus that border, so you use the outer dimensions.

Outer length = pool length + 2 × walkway width

Outer width = pool width + 2 × walkway width

Perimeter of the walkway equals the outer rectangle’s perimeter: 2 × (outer length + outer width).

If the pool is 20 by 12 and the walkway is 3 feet wide, then:

outer length = 20 + 2×3 = 26

outer width = 12 + 2×3 = 18

Perimeter = 2 × (26 + 18) = 2 × 44 = 88 feet.