McGraw Hill Glencoe Geometry, 2012
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McGraw Hill Glencoe Geometry, 2012 View details
1. Areas of Parallelograms and Triangles
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Exercise 2 Page 783

The perimeter of a parallelogram is calculated by adding the lengths of its four sides. The area of a parallelogram is calculated by multiplying the base by the height.

Perimeter: 76ft
Area: 288ft^2

Practice makes perfect

A parallelogram is a quadrilateral where both of the pairs of opposite sides are parallel and congruent. Any side can be called the base of the parallelogram. Its height is the perpendicular distance between any two parallel bases. For the given parallelogram, we will find its perimeter and area one at a time.

Perimeter

The perimeter of a parallelogram is calculated by adding its four side lengths.

We are given that lengths of two adjacent sides of the parallelogram are 20 feet and 18 feet, but we are missing the two other measurements. However, the opposite sides of parallelograms are congruent, so we know that their lengths are also 20 feet and 18 feet.

Now we can add the four side lengths to obtain the perimeter. Perimeter: 20+18+20+18=76 ft

Area

The area of a parallelogram is the product of a base and its corresponding height. We can consider the side whose length is 18 feet as the base and the height is 16 feet.

Now we can substitute lengths of the base and the height into the formula for the area of a parallelogram and simplify.
A=bh
A=( 18)( 16)
A=288
The area of the parallelogram is 288 square feet.