Build an equation to calculate the surface area of a equilateral triangular prism

1 answer

To calculate the surface area of an equilateral triangular prism, we need to consider both the lateral surface area and the area of the two triangular bases.

  1. Base Area: The base of the prism is an equilateral triangle. If the side length of the triangle is \( s \), the area (\( A \)) of one equilateral triangle can be calculated using the formula: \[ A = \frac{\sqrt{3}}{4} s^2 \]

  2. Lateral Surface Area: The lateral surface area (the area of the three rectangular sides) can be calculated by multiplying the perimeter of the triangular base by the height (\( h \)) of the prism. The perimeter \( P \) of an equilateral triangle with side length \( s \) is: \[ P = 3s \] Thus, the lateral surface area (\( LSA \)) is: \[ LSA = P \times h = 3s \times h = 3sh \]

  3. Total Surface Area: The total surface area (\( SA \)) of the prism can be found by adding the lateral surface area and the areas of the two bases: \[ SA = LSA + 2 \times A \] Putting it all together: \[ SA = 3sh + 2 \left( \frac{\sqrt{3}}{4} s^2 \right) \]

Simplifying the equation gives us: \[ SA = 3sh + \frac{\sqrt{3}}{2} s^2 \]

Thus, the final equation for the surface area of an equilateral triangular prism is: \[ SA = 3sh + \frac{\sqrt{3}}{2} s^2 \]