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

240 cm2
240 cm squared

184 cm2
184 cm squared

324 cm2
324 cm squared

84 cm2

84 cm squared

To find the total surface area of the triangular prism tent, we need to calculate the area of the two triangular faces and the three rectangular faces.

Area of triangular faces:
2 * (1/2 * base * height) = 2 * (1/2 * 4 * 6) = 2 * 12 = 24 cm squared

Area of rectangular faces:
2 * (base * height) + (base * length) = 2 * (4 * 6) + (4 * 12) = 2 * 24 + 48 = 96 + 48 = 144 cm squared

Total surface area = 24 + 144 = 168 cm squared

Fabric area purchased = 18 * 18 = 324 cm squared

Fabric remaining = Fabric area purchased - Total surface area = 324 - 168 = 156 cm squared