Use the image to answer the question.

there is a triangular prism there measurements are 4 cm, 12 cm, 7 cm, and 6 cm
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?
A. 324 cm squared
B. 240 cm squared
C. 84 cm squared
D. 184 cm squared

1 answer

To find the surface area of the triangular prism, we need to find the area of each face and then add them together.

First, find the area of the triangular bases:
Area = (1/2) * base * height
Area = (1/2) * 6 cm * 4 cm = 12 cm squared

Since there are two triangular bases, the total area for the bases is:
2 * 12 cm squared = 24 cm squared

Next, find the area of the three rectangular faces:
Face 1: 12 cm * 7 cm = 84 cm squared
Face 2: 6 cm * 7 cm = 42 cm squared
Face 3: 4 cm * 12 cm = 48 cm squared

Add the areas of the three rectangular faces:
84 cm squared + 42 cm squared + 48 cm squared = 174 cm squared

Now, add the total area for the bases and the total are for the three faces:
24 cm squared (base) + 174 cm squared (faces) = 198 cm squared

Since Jordan purchased fabric that is 18 cm by 18 cm, the total area of the fabric is:
18 cm * 18 cm = 324 cm squared

To find out how much fabric will be left over, subtract the surface area of the triangular prism from the total area of the fabric:
324 cm squared (total fabric) - 198 cm squared (triangular prism) = 126 cm squared

Therefore, the answer is:
C. 126 cm squared