1. Calculate the length of one side of a rectangle, in feet that has a perimeter of 280 ft and a width of 20 ft.

2. Calculate the diameter of the circle, in feet with a 94.2 ft circumference.

3. Calculate the diameter of a circle, in feet, with an area of 19.625 sqft.

4. Find the length of one side of a rectangle, in feet, that has an area of 2400 sqft and is 20 ft wide.

5. You have 1 gallon of paint to paint both sides of an 8-ft tall fence that is 45 ft long. If one gallon covers 400 sqft, you have enough paint?

Answers:

1. 120 ft
The perimeter is the outside measurements. Normally, it is L + L + W + W = Per. But since we were given the Perimeter we need to rearrange the formula. Add together what information is given = 20 ft + 20 ft = 40 ft, now subtract the number you just found from the given Perimeter = 280 ft – 40 ft = 240 ft (but that is for both sides combined), the question asked for only 1 side. Must divide the 240 ft in half to get the answer = (240 ft) / (2) =

2. 30 ft
To find the circumference of a circle = 3.14 X D, ft, so to find the missing number (diameter) = (94.2 ft) / (3.14) =

3. 5 ft
This one is a little tricky. To find the area of a circle, sqft = 3.14 X R, ft X R, ft or 0.785 X D, ft X D, ft, so if the area is 19.625 sqft we will divide by the only number we have = (19.625 sqft) / (0.785) = 25 Now find the square root of 25 (what times itself will total 25?)

4. 120 ft
The formula for area, sqft = L X W, so (2400 sqft) / (20 ft) =

5. No, you need 1 more gallon
8′ X 45′ = 360 sqft

NOTE: Those who took my class – you can use the Davidson Pie Chart for these