FiveMinute Check over Lesson 4 8 Main Idea

Five-Minute Check (over Lesson 4– 8) Main Idea and Vocabulary Example 1: Use Shadow Reckoning Example 2: Use Indirect Measurement

• Solve problems involving similar triangles. • indirect measurement

Use Shadow Reckoning TREES A tree in front of Marcel’s house has a shadow 12 feet long. Marcel’s shadow is 3 feet long. If Marcel is 5. 5 feet tall, how tall is the tree?

Use Shadow Reckoning tree’s shadow Marcel’s shadow 12 ● 5. 5 = 3 ● h tree’s height Marcel’s height Find the cross products. Multiply. Divide each side by 3. Simplify. Answer: The tree is 22 feet tall.

Jayson casts a shadow that is 10 feet long. At the same time, a flagpole casts a shadow that is 40 feet long. If the flagpole is 20 feet tall, how tall is Jayson? A. 4. 5 feet B. 5 feet C. 5. 5 feet D. 6 feet 1. 2. 3. 4. A B C D

Use Indirect Measurement SURVEYING The two triangles shown in the figure are similar. Find the distance d across the stream.

Use Indirect Measurement Write a proportion. AB = 48, ED = d, BC = 60, and DC = 20 48 ● 20 = d ● 60 Find the cross products. Multiply. Then divide each side by 60. Simplify. Answer: The distance across the stream is 16 meters.

SURVEYING The two triangles shown in the figure are similar. Find the distance d across the stream. A. 6 feet B. 6. 5 feet C. 7 feet D. 7. 5 feet 1. 2. 3. 4. A B C D

End of the Lesson

Five-Minute Check (over Lesson 4– 8) Image Bank Math Tools Solving Proportions Dilations Similar Triangles

(over Lesson 4 -8) Find the coordinates of the image of the parallelogram ABCD after a dilation with a scale factor of 2. Parallelogram ABCD has vertices at A(1, 1), B(3, 3), C(6, 3), D(4, 1). A. A′(2, 2), B′(6, 6), C′(12, 6), D′(8, 2) B. A′(1, 2), B′(5, 6), C′(12, 12), D′(8, 2) C. A′(6, 6), B′(2, 2), C′(12, 6), D′(2, 8) D. A′(2, 2), B′(6, 6), C′(6, 12), D′(8, 2) 1. 2. 3. 4. A B C D

(over Lesson 4 -8) A. B. C. D. 1. 2. 3. 4. A B C D

(over Lesson 4 -8) Parallelogram ABCD has vertices at A(1, 1), B(3, 3), C(6, 3), D(4, 1). Identify whether the image of parallelogram ABCD after a dilation with a scale factor of 2 is an enlargement or a reduction. A. enlargement B. reduction C. cannot be determined 1. 2. 3. A B C

(over Lesson 4 -8) A. enlargement B. reduction C. cannot be determined 1. 2. 3. A B C

(over Lesson 4 -8) Triangle M is similar to triangle N. What scale factor was used to dilate triangle N to M? A. 3 B. 2 C. D. 1. 2. 3. 4. A B C D