Question

(05.07) A square pyramid is shown. What is the surface area?

Answer 1

Answer:

C. $31.25\text{ cm}^2$.

Step-by-step explanation:

We have been given a square pyramid. We are asked to find surface area of our given pyramid.

The surface area of pyramid will be equal to area of base plus area of four triangular faces.

Area of base of square will be $(2.5\text{ cm})^2=6.25\text{ cm}^2$.

$\text{Area of triangular face}=\frac{1}{2}\times 2.5\text{ cm}\times 5\text{ cm}$

$\text{Area of triangular face}=2.5\times 2.5\text{ cm}^2$

$\text{Area of triangular face}=6.25\text{ cm}^2$

The area of 4 triangular faces will be 4 times area of each triangular face.

$\text{Area of 4 triangular faces}=4\times 6.25\text{ cm}^2$

$\text{Area of 4 triangular faces}=25\text{ cm}^2$

We know that area of pyramid would be area of base and area of 4 triangular faces.

$\text{Surface area of pyramid}=6.25\text{ cm}^2+25\text{ cm}^2$

$\text{Surface area of pyramid}=31.25\text{ cm}^2$

Therefore, the surface area of our given pyramid is 31.25 square centimeters.

Answer 2

Area of a triangle equals 1/2 Bh

base = 2.5 height = 5

2.5 x 5 = 12.5/2 = 6.25

since there are 4 sides you multiply by 4

6.25 x 4 = 25

Now to do the bottom you multiply 2.5 x 2.5 = 6.25

6.25 + 25 = 31.25<----ANSWER

Hope this helps