Use the image to answer the question.
An illustration shows a 3 D triangular prism. The edges that are not visible are represented by dashed lines. The length and base of the triangular prism measures 12 centimeters and 4 centimeters. The perpendicular height h measures 6 centimeters, and the sides of the triangular face measures 7 centimeters.
Jordan purchased a piece of fabric that is 18 cm by 18 cm in order to make a tent for her little sister’s dolls. Using the dimensions for the tent shaped as a triangular prism, how much fabric will be left over?
(1 point)
Responses
84 cm2
84 cm squared
184 cm2
184 cm squared
240 cm2
240 cm squared
324 cm2
324 cm squared
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Since the triangular prism has a length of 12 cm, a base of 4 cm, and a height of 6 cm, the total surface area of the fabric needed to make the tent is:
2(1/2 * base * height) + (base * length) = 2(1/2 * 4 * 6) + (4 * 12) = 2(12) + 48 = 24 + 48 = 72 cm²
Since Jordan purchased a piece of fabric that is 18 cm by 18 cm (324 cm²) and she needs 72 cm² to make the tent, the amount of fabric left over will be:
324 cm² - 72 cm² = 252 cm²
Therefore, the correct answer is:
240 cm²