Question

a lawn is in the shape of a trapezoid with a height of 40 feet and bases of 80 feet and 120 feet. how many bags of fertilizer must be purchased to cover the lawn if each bag covers 2500 square feet? (round up to the nearest bag.)

Explanation:

Step1: Calculate area of trapezoid

The formula for the area of a trapezoid is $A=\frac{(b_1 + b_2)h}{2}$, where $b_1 = 80$ feet, $b_2=120$ feet and $h = 40$ feet. So $A=\frac{(80 + 120)\times40}{2}=\frac{200\times40}{2}=4000$ square - feet.

Step2: Calculate number of bags

If each bag covers 2500 square - feet, then the number of bags $n=\frac{4000}{2500}=1.6$.

Step3: Round up

Since we can't buy a fraction of a bag, we round up to the nearest whole number. So $n = 2$.

Answer:

2