Section B Section B Checkpoint

Problem 1

This figure has one line of symmetry. What is the perimeter of the shape? Explain or show your reasoning.

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Solution

78 inches. Sample response: The line of symmetry tells me the unlabelled side is 24 inches and $12 + 18 + 24 + 24 = 78$ .

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Sample Response

78 inches. Sample response: The line of symmetry tells me the unlabelled side is 24 inches and $12 + 18 + 24 + 24 = 78$ .

Problem 2

This shape has 4 lines of symmetry and a perimeter of 36 cm. What is the length of each of the sides? Explain or show your reasoning.

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Solution

9 cm. Sample response: If the shape has 4 lines of symmetry, then the 4 side lengths are all equal. 36 cm divided by 4 is 9 cm for each side or $9+9+9+9=36$ .

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Sample Response

9 cm. Sample response: If the shape has 4 lines of symmetry, then the 4 side lengths are all equal. 36 cm divided by 4 is 9 cm for each side or $9+9+9+9=36$ .