An illustration shows a net version of a triangular prism. The net model shows 3 rectangles top to bottom. Identical triangles are attached to the left and right of the middle rectangle. Parts are labeled with measurements. The top and bottom rectangles have a length measuring 10 centimeters and a width measuring 5 centimeters. The perpendicular height from the top vertex of the triangle to the base measures 4 centimeters. The base of the triangle measures 5 centimeters. The base shares an edge with the middle rectangle.

What is the surface area of the net of the triangular prism?

(1 point)
__square centimeters

1 answer

To find the surface area of the triangular prism, we will calculate the area of all the faces in the net.

  1. Identify the dimensions:

    • The top and bottom rectangles each have a length of 10 cm and a width of 5 cm.
    • The middle rectangle (the lateral face) has a length of 10 cm and a height of 5 cm.
    • The triangular faces have a base of 5 cm and a height of 4 cm.
  2. Calculate the area of the rectangles:

    • Top rectangle: \[ \text{Area} = \text{length} \times \text{width} = 10 , \text{cm} \times 5 , \text{cm} = 50 , \text{cm}^2 \]
    • Bottom rectangle: \[ \text{Area} = 10 , \text{cm} \times 5 , \text{cm} = 50 , \text{cm}^2 \]
    • Middle rectangle (lateral face): \[ \text{Area} = 10 , \text{cm} \times 5 , \text{cm} = 50 , \text{cm}^2 \]
  3. Calculate the area of the triangular faces:

    • Area of one triangle using the formula \(\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}\): \[ \text{Area} = \frac{1}{2} \times 5 , \text{cm} \times 4 , \text{cm} = \frac{1}{2} \times 20 , \text{cm}^2 = 10 , \text{cm}^2 \]
    • Since there are two identical triangular faces, the total area of both triangles is: \[ 2 \times 10 , \text{cm}^2 = 20 , \text{cm}^2 \]
  4. Total surface area of the prism: \[ \text{Total Surface Area} = \text{Area of top rectangle} + \text{Area of bottom rectangle} + \text{Area of lateral rectangle} + \text{Area of triangles} \] \[ = 50 , \text{cm}^2 + 50 , \text{cm}^2 + 50 , \text{cm}^2 + 20 , \text{cm}^2 = 220 , \text{cm}^2 \]

So the surface area of the net of the triangular prism is 220 square centimeters.