Download presentation

Presentation is loading. Please wait.

Published byAllyson Short Modified over 6 years ago

1
EXAMPLE 2 Use a ratio to find a dimension SOLUTION Painting You are planning to paint a mural on a rectangular wall. You know that the perimeter of the wall is 484 feet and that the ratio of its length to its width is 9 : 2. Find the area of the wall. Write expressions for the length and width. Because the ratio of length to width is 9 : 2, you can represent the length by 9x and the width by 2x. STEP 1

2
EXAMPLE 2 Use a ratio to find a dimension STEP 2 Solve an equation to find x. Formula for perimeter of rectangle Substitute for l, w, and P. Multiply and combine like terms. Divide each side by 22. =2l + 2wP = 2(9x) + 2(2x) 484 = 22x Evaluate the expressions for the length and width. Substitute the value of x into each expression. STEP 3 The wall is 198 feet long and 44 feet wide, so its area is 198 ft 44 ft = 8712 ft. 2 = 22x Length = 9x = 9(22) = 198 Width = 2x = 2(22) = 44

3
EXAMPLE 3 Use extended ratios Combine like terms. SOLUTION Triangle Sum Theorem Divide each side by 6. =30x = 6x6x180 = o x + 2x + 3x ooo ALGEBRA The measures of the angles in CDE are in the extended ratio of 1 : 2 : 3. Find the measures of the angles. Begin by sketching the triangle. Then use the extended ratio of 1 : 2 : 3 to label the measures as x°, 2x°, and 3 x°. The angle measures are 30, 2(30 ) = 60, and 3(30 ) = 90. oo oo o ANSWER

4
GUIDED PRACTICE for Examples 2 and 3 3. The perimeter of a room is 48 feet and the ratio of its length to its width is 7 : 5. Find the length and width of the room. SOLUTION Write expressions for the length and width. Because the ratio of length is 7 : 5, you can represent the length by 7x and the width by 5x. STEP 1

5
GUIDED PRACTICE for Examples 2 and 3 STEP 2 Solve an equation to find x. Formula for perimeter of rectangle Substitute for l, w, and P. Multiply and combine like terms. =2l + 2wP = 2(7x) + 2(5x) 48 = 24x= 2x Evaluate the expressions for the length and width. Substitute the value of x into each expression. STEP 3 Length = 7x + 7(2) = 14 ft Width = 5x + 5(2) = 10 ft

6
GUIDED PRACTICE for Examples 2 and 3 Begin by sketching the triangle. Then use the extended ratio of 1 : 3 : 5 to label the measures as x°, 2x°, and 3 x°. Triangle Sum Theorem SOLUTION Combine like terms. Divide each side by 9. =20x = 9x9x180 = x + 3x + 5x 180 oo o o 4. A triangle’s angle measures are in the extended ratio of 1 : 3 : 5. Find the measures of the angles. x 3x 5x The angle measures are 20, 3(20 ) = 60, and 5(20 ) = 100. oo oo o ANSWER

Similar presentations

© 2021 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google