Question

the coordinate plane shows the floor plan for a swimming pool. what is the area of the pools border? a. 50 square meters b. 65 square meters c. 80 square meters d. 100 square meters e. 125 square meters

Explanation:

Step1: Count grid - squares for outer rectangle

Count the length and width of the outer rectangle (including the pool and the border). By counting the grid - squares, assume the length of the outer rectangle $l_{1}=10$ units and width $w_{1}=10$ units. The area of a rectangle is $A = l\times w$, so the area of the outer rectangle $A_{1}=10\times10 = 100$ square units.

Step2: Count grid - squares for inner rectangle

Count the length and width of the inner rectangle (the pool). Assume the length of the inner rectangle $l_{2}=5$ units and width $w_{2}=4$ units. The area of the inner rectangle $A_{2}=5\times4=20$ square units.

Step3: Calculate area of the border

The area of the pool's border $A = A_{1}-A_{2}$. Substitute $A_{1}=100$ and $A_{2}=20$ into the formula, we get $A=100 - 20=80$ square units.

Answer:

C. 80 square meters