Question

a square pyramid has a base with side lengths each measuring 40 inches. the pyramid is 21 inches tall, with a slant height of 29 inches. what is the surface area of the pyramid? \bigcirc 3,280 inches \bigcirc 3,280 square inches \bigcirc 3,920 inches \bigcirc 3,920 square inches

Explanation:

Step1: Calculate base area

$\text{Base Area} = 40 \times 40 = 1600$ square inches

Step2: Calculate one triangular face area

$\text{Single Triangle Area} = \frac{1}{2} \times 40 \times 29 = 580$ square inches

Step3: Calculate total lateral area

$\text{Total Lateral Area} = 4 \times 580 = 2320$ square inches

Step4: Calculate total surface area

$\text{Total Surface Area} = 1600 + 2320 = 3920$ square inches

Answer:

3,920 square inches