Question

A square pyramid has a base side of 12 cm and a slant height of 10 cm. Find its lateral surface area.

• A. 240 cm²
• B. 120 cm²
• C. 480 cm²
• D. 360 cm²

Answer 1

Answer:

A. 240 cm²

To find the lateral surface area of a square pyramid, we use the formula:

$LSA = 2 \cdot s \cdot l$

Where:

• $s$ = length of the base side ($12\text{ cm}$)

• $l$ = slant height ($10\text{ cm}$)

(Alternatively, the lateral surface area is the sum of the areas of the 4 triangular faces: $4 \times (\frac{1}{2} \times s \times l) = 2sl$.)

Step-by-Step Calculation

1. Substitute the given values into the formula:

   $LSA = 2 \times 12\text{ cm} \times 10\text{ cm}$

2. Calculate the product:

   $LSA = 24 \times 10 = 240\text{ cm}^2$

Answer

The lateral surface area of the square pyramid is $240\text{ cm}^2$.