Exercise 90 Page 352

Practice makes perfect

Consider the given diagram of the parallelogram.

We will calculate the perimeter and area one at a time.

Perimeter

The perimeter of a figure is the sum of its side lengths. A parallelogram has two pairs of equal sides, so we can find its perimeter using the following formula. P=2l+2w In this formula, l is the length of the base and w is the width. From the picture, we know that l is equal to 20.2 centimeters and w is equal to 14 centimeters.

P=2l+2w

SubstituteII

l= 20.2, w= 14

P=2( 20.2)+2( 14)

Multiply

P=40.4+28

AddTerms

Add terms

P=68.4

The perimeter of the parallelogram is 68.4 centimeters.

Area

Now we can find the area of a parallelogram. We will use the following formula to do it. A=l * h In this formula, l is the length of the base and h is the height. For our parallelogram, we will substitute b= 20.2 for the base and h= 12 for the height into the formula to calculate A.

A=l * h

SubstituteII

b= 20.2, h= 12

A=( 20.2)( 12)

Multiply

A=242.4

The area of the parallelogram is 242.4 square centimeters.

Let's take a look at the given trapezoid.

Let's calculate the perimeter and area separately.

Perimeter

In general, the perimeter of a figure is the sum of its side lengths. P=6m+7m+7.5m+17.8m ⇓ P=38.3 m The trapezoid's perimeter is 38.3 meters.

Area

To find the area of the trapezoid, we will use the formula for calculating the area of trapezoid. A=b_1+b_2/2* h In this formula, b_1 is the length of the base 1, b_2 is the length of the base 2, and h is the height of the trapezoid. We will substitute b_1= 7, b_2= 17.8, and h= 4 into the formula to calculate A.

A=b_1+b_2/2* h

SubstituteValues

Substitute values

A=7+ 17.8/2( 4)

AddTerms

Add terms

A=24.8/2(4)

MoveRightFacToNum

a/c* b = a* b/c

A=24.8(4)/2

Multiply

A=99.2/2