Use the image to answer the question.

An illustration shows a triangular prism. The front triangular face is visible. The right rectangular face is visible. The sides and edges that are not visible are indicated by dashed lines. Parts are labeled with measurements. The left side of the triangle measures 10 centimeters. The right side of the triangle also measures 10 centimeters. The perpendicular height from the top vertex of the triangle to the base measures 6 centimeters. The base of the triangle measures 8 centimeters.

What is the missing length l
of the triangular prism if the surface area is 524 square centimeters?

(1 point)
Responses

10 cm
10 cm

17 cm
17 cm

8 cm
8 cm

16 cm
16 cm
Skip to navigation

1 answer

To find the missing length \( l \) of the triangular prism given that the surface area is 524 square centimeters, we first need to calculate the surface area of the prism.

  1. Calculate the area of the triangular base:

    • The base of the triangle measures 8 cm, and the height from the top vertex to the base measures 6 cm.
    • Area of the triangle \( A = \frac{1}{2} \times \text{base} \times \text{height} \): \[ A = \frac{1}{2} \times 8 , \text{cm} \times 6 , \text{cm} = \frac{48}{2} , \text{cm}^2 = 24 , \text{cm}^2 \]
  2. Calculate the surface area of the prism:

    The surface area \( SA \) of a triangular prism is given by: \[ SA = 2 \times \text{Area of the triangular base} + \text{Perimeter of the triangular base} \times \text{Height of the prism} \]

    • The perimeter \( P \) of the triangle is calculated as: \[ P = 8 , \text{cm} + 10 , \text{cm} + 10 , \text{cm} = 28 , \text{cm} \]
    • Substituting into the surface area formula: \[ SA = 2 \times 24 , \text{cm}^2 + 28 , \text{cm} \times l \] \[ SA = 48 , \text{cm}^2 + 28l \]
  3. Set the equation equal to the given surface area: \[ 48 , \text{cm}^2 + 28l = 524 , \text{cm}^2 \] \[ 28l = 524 - 48 \] \[ 28l = 476 \] \[ l = \frac{476}{28} = 17 \]

Thus, the missing length \( l \) of the triangular prism is \( 17 , \text{cm} \).

The answer is: 17 cm