A stereo system in the shape of a triangular pyramid has a height of 7.5 inches. The area of the base of the speaker is 12 square inches. 

 
What is the volume of the speaker in cubic inches?

1 answer

To find the volume of a triangular pyramid (also known as a tetrahedron), you can use the formula:

\[ V = \frac{1}{3} \times \text{Base Area} \times \text{Height} \]

In this case, the area of the base is given as 12 square inches and the height is 7.5 inches. Plugging in the values:

\[ V = \frac{1}{3} \times 12 , \text{sq in} \times 7.5 , \text{in} \]

Calculating this step by step:

  1. Multiply the base area by the height: \[ 12 \times 7.5 = 90 \]

  2. Now, multiply by \(\frac{1}{3}\): \[ V = \frac{1}{3} \times 90 = 30 \]

Therefore, the volume of the speaker is:

\[ \boxed{30} , \text{cubic inches} \]