Exercise 32 Page 329

Practice makes perfect

Consider the given diagram of the triangle.

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

Perimeter

The perimeter of a figure is the sum of its side lengths. For a triangle, this is the sum of sides a, b, and c. P=a+b+c In our case, we will substitute a= 15, b= 14, and c= 12, into the formula and simplify.

P=a+b+c

SubstituteValues

Substitute values

P= 15+ 14+ 12

AddTerms

Add terms

P=41

The perimeter of the triangle is 41 centimeters.

Area

Now we can find the area of a triangle. We will use the following formula to do it. A=1/2bh In this formula, b is the length of the base and h is the height. For our triangle, we will substitute b= 14 for the base and h= 11.3 for the height into the formula to calculate A.

A=1/2bh

SubstituteII

b= 14, h= 11.3

A=1/2( 14)( 11.3)

MoveRightFacToNum

a/c* b = a* b/c

A=14/2* 11.3

CalcQuot

Calculate quotient

A=7 * 11.3

Multiply

A=79.1

The area of the triangle is 79.1 square centimeters.

Consider the given diagram of the triangle.

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

Perimeter

The perimeter of a figure is the sum of its side lengths. For a triangle, this is the sum of sides a, b, and c. P=a+b+c In our case, we will substitute a= 20, b= 25, and c= 15, into the formula and simplify.

P=a+b+c

SubstituteValues

Substitute values

P= 20+ 25+ 15

AddTerms

Add terms

P=60

The perimeter of the triangle is 60 inches.

Area

Now we can find the area of a triangle. We will use the following formula to do it. A=1/2bh In this formula, b is the length of the base and h is the height. For our triangle, we will substitute b= 25 for the base and h= 12 for the height into the formula to calculate A.

A=1/2bh

SubstituteII

b= 25, h= 12

A=1/2( 25)( 12)

MoveRightFacToNum

a/c* b = a* b/c

A=25/2* 12

MoveRightFacToNum

a/c* b = a* b/c

A=25* 12/2

Multiply

A=300/2