The perimeter of a rectangle is 20km and the length is 800m. What is the area of the rectangle?

Question

Quizplus · Accepted Answer

First we must find the length and width of the rectangle. If the perimeter = 20km, then: 20km = Length + Width + Length + Width Since there are 2 lengths and 2 widths (4 sides total), we can simplify this equation to: 20km = 2(length) + 2(width) Step 1: Plug in values from the problem. We are given the length (800 meters, which we can convert to 0.8 km), so we know we need to solve for the width. This is the unknown value we are trying to find, so we will assign it the variable x. 20 = 2(0.8) + 2x 20 = 1.6 + 2x Step 2: Solve for x. Subtract 1.6 from both sides to move the 1.6.km to the left side of the equation. 20km -1.6km = 2x + 1.6km - 1.6km 18.4 = 2x In order to isolate the variable completely, divide both sides of the equation by 2. 18.4 ÷ 2 = 2x ÷ 2 x = 9.2km Now, we have all of the necessary information to determine the area of the rectangle. Length: 0.8km Width: 9.2km To calculate the area of a rectangle we use the following formula: area = length x width = 0.8km x 9.2km = 7.36 km² The units of area are the units of length squared since we are multiplying two units of length (e.g. m • m).

The Perimeter of a Rectangle Is 20km and the Length