Exercise 4 Page 287

To find the area of the parallelogram, calculate the product of the base and the height. Use the conversion factor to convert from meters to centimeters.

400 000cm^2

Practice makes perfect

The area of a parallelogram is the product of its base and its height. In the given parallelogram, the length of the base is 4 meters and the height is 10 meters.

Let's substitute these two values into the formula for the area of a parallelogram and simplify.

A=bh

SubstituteII

b= 4, h= 10

A= 4( 10)

Multiply

A=40

The area of the parallelogram is 40 square meters. Now we want to convert this into square centimeters. Let's consider how best to do this. (1 m)(1 m)=1 m^2 ⇕ (100 cm)(100 cm)=10 000 cm^2 Converting between square meters ( m^2) and square centimeters ( cm^2) will involve using a conversion factor. 10 000cm^2/1 m^2 If we multiply 40m^2 by this conversion, we will have an equivalent value in square centimeters. Let's do it!

40m^2 * 10 000cm^2/1 m^2

MoveLeftFacToNum

a*b/c= a* b/c

40m^2 * 10 000cm^2/1 m^2

CrossCommonFac

Cross out common factors

40 m^2 * 10 000cm^2/1 m^2

SimpQuot

Simplify quotient

40* 10 000 cm^2/1

DivByOne

a/1=a