body{margin:0;} noscript{z-index: 10000; position: fixed; display: block; height: 100%; width: 100%; background: #fff;} noscript .fa{font-size: 40px; display:block; color: #daa520;} noscript div{margin-top: 6%; padding-left: 20px; padding-right: 20px; text-align: center;} ! You must have JavaScript enabled to use this site.

McGraw Hill Glencoe Geometry, 2012

MH

McGraw Hill Glencoe Geometry, 2012 View details

2. Areas of Trapezoids, Rhombi, and Kites

Continue to next subchapter

Exercise 21 Page 794

The area of a trapezoid is one half of the product of its height and the sum of its bases.

4m

Practice makes perfect

We are told that a trapezoid has a height of 8m, a base length of 12m, and an area of 64 square meters. Let's draw a diagram to illustrate this situation.

The area of a trapezoid is one half the product of its height and the sum of its bases. A=1/2h(b_1+b_2) We can substitute the known values into this formula and solve for the length of the second base b_1. Let's do it!

A=1/2h(b_1+b_2)

SubstituteValues

Substitute values

64=1/2(8)(b_1+ 12)

▼

Solve for x

MoveRightFacToNumOne

1/b* a = a/b

64=8/2(b_1+12)

Calculate quotient

64=4(b_1+12)

.LHS /4.=.RHS /4.

16=b_1+12

LHS-12=RHS-12

4=b_1

Rearrange equation

b_1=4

The length of the second base of the trapezoid is 4 meters.

Subchapter links

Check Your Understanding p.793

H.O.T. Problems p.795

Standardized Test Practice p.796

Spiral Review p.796

Skills Review p.796