1 / 14

5-8

Using Similar Figures. 5-8. Course 2. Warm Up. Problem of the Day. Lesson Presentation. 5-8. Using Similar Figures. JN. KO. Course 2. Warm Up. Solve each proportion. 24 x. 6 19. k 4. 75 25. x = 76. k = 12. 2. 1. =. =.

erandolph
Download Presentation

5-8

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Using Similar Figures 5-8 Course 2 Warm Up Problem of the Day Lesson Presentation

  2. 5-8 Using Similar Figures JN KO Course 2 Warm Up Solve each proportion. 24 x 6 19 k 4 75 25 x = 76 k = 12 2. 1. = = Triangles JNZ and KOA are similar. Identify the side that corresponds to the given side of the similar triangles. 3. A J Z O K N

  3. 5-8 Using Similar Figures Course 2 Problem of the Day Harvey starts to fill a 3-gallon tank from a hose that delivers 1 gallon per minute. However, the tanks leaks 1 quart per minute. In how many minutes will the tank begin to overflow? 4

  4. 5-8 Using Similar Figures Course 2 Learn to use similar figures to find unknown lengths.

  5. 5-8 Using Similar Figures Course 2 Insert Lesson Title Here Vocabulary indirect measurement

  6. 5-8 Using Similar Figures Course 2 Indirect measurementis a method of using proportions to find an unknown length or distance in similar figures.

  7. 5-8 Using Similar Figures Course 2 Additional Example 1: Finding Unknown Lengths in Similar Figures Find the unknown length in similar figures. AC QS AB QR = Write a proportion using corresponding sides. 14 w 12 48 = Substitute lengths of the sides. 12 · w = 48 · 14 Find the cross product. Multiply. 12w = 672 672 12 12w 12 = Divide each side by 12 to isolate the variable. w = 56 QR is 56 centimeters.

  8. 5-8 Using Similar Figures Course 2 Insert Lesson Title Here Check It Out: Example 1 Find the unknown length in similar figures. x Q R 10 cm B A 24 cm 12 cm D C T S AC QS AB QR = Write a proportion using corresponding sides. 10 x 12 24 Substitute lengths of the sides. = Find the cross product. 12 · x = 24 · 10 12x = 240 Multiply. 240 12 12x 12 Divide each side by 12 to isolate the variable. = x = 20 QR is 20 centimeters.

  9. 5-8 Using Similar Figures Course 2 Insert Lesson Title Here Additional Example 2: Measurement Application The inside triangle is similar in shape to the outside triangle. Find the length of the base of the inside triangle. Let x = the base of the inside triangle. 8 2 12 x Write a proportion using corresponding side lengths. = 8 · x = 2 · 12 Find the cross products. Multiply. 8x = 24 8x 8 24 8 = Divide each side by 8 to isolate the variable. x = 3 The base of the inside triangle is 3 inches.

  10. 5-8 Using Similar Figures Course 2 Insert Lesson Title Here Check It Out: Example 2 The rectangle on the left is similar in shape to the rectangle on the right. Find the width of the right rectangle. 12 cm 6 cm 3 cm ? Let w = the width of the right rectangle. 6 12 3 w Write a proportion using corresponding side lengths. = 6 ·w = 12 · 3 Find the cross products. Multiply. 6w = 36 36 6 6w 6 = Divide each side by 6 to isolate the variable. w = 6 The right rectangle is 6 cm wide.

  11. 5-8 Using Similar Figures Course 2 Additional Example 3: Estimating with Indirect Measurement City officials want to know the height of a traffic light. Estimate the height of the traffic light. 48.75 h 27.25 15 = Write a proportion. 27 15 Use compatible numbers to estimate. 49 h ≈ h ft 9 5 49 h Simplify. ≈ 27.25 ft Cross multiply. 9h ≈ 245 48.75 ft Multiply each side by 9 to isolate the variable. h ≈ 27 The traffic light is about 30 feet tall.

  12. 5-8 Using Similar Figures Course 2 Check It Out: Example 3 The inside triangle is similar in shape to the outside triangle. Find the height of the outside triangle. h 30.25 5 14.75 = Write a proportion. Use compatible numbers to estimate. 5 15 h 30 ≈ h ft 5 ft 13 h 30 ≈ Simplify. Cross multiply. 1 • 30≈ 3• h 14.75 ft Multiply each side by 5 to isolate the variable. 30≈ 3h 30.25 ft 10≈ h The outside triangle is about 10 feet tall.

  13. 5-8 Using Similar Figures Course 2 Insert Lesson Title Here Lesson Quiz: Part I Find the unknown length in each pair of similar figures. 1. x = 120 cm 2. t = 150 cm

  14. 5-8 Using Similar Figures Course 2 Insert Lesson Title Here Lesson Quiz: Part II Find the unknown length in each pair of similar figures. 3. The width of the smaller rectangular cake is 5.75 in. The width of a larger rectangular cake is 9.25 in. Estimate the length of the larger rectangular cake. x = 15 inches

More Related