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

184 cm2

240 cm2

324 cm2

1 answer

The tent shape consists of two triangular ends and three rectangular sides.

The two triangular ends:
Area = 1/2 * base * height
Area = 1/2 * 18 cm * 18 cm
Area = 162 cm^2 for both triangular ends

The three rectangular sides:
The base of the triangular prism is 18 cm and the height is also 18 cm.
Each rectangular side is a rectangle with a length of 18 cm and width of 18 cm.
So the area of 1 rectangular side = length * width = 18 cm * 18 cm = 324 cm^2
Area of 3 rectangular sides = 3 * 324 cm^2 = 972 cm^2

Total fabric used = area of two triangular ends + area of three rectangular sides = 162 cm^2 + 972 cm^2 = 1134 cm^2

Fabric remaining = Total fabric purchased - Total fabric used
Fabric remaining = 18 cm * 18 cm - 1134 cm^2 = 324 cm^2

Therefore, 324 cm^2 of fabric will be left over.

The correct answer is 324 cm2.