Question: A right square pyramid has a surface area of 50.75 square inches and a base length of 3.5 inches.
a. Sketch and label a diagram of the pyramid.
1. **Problem Statement:**
We have a right square pyramid with a surface area of $50.75$ square inches and a base length of $3.5$ inches.
2. **Understanding the Pyramid:**
A right square pyramid has a square base and four triangular faces meeting at a single apex above the center of the base.
3. **Surface Area Formula:**
The surface area $S$ of a right square pyramid is given by:
$$S = B + L$$
where $B$ is the area of the square base and $L$ is the lateral surface area.
4. **Calculate Base Area $B$:**
Since the base is a square with side length $3.5$ inches,
$$B = (3.5)^2 = 12.25 \text{ square inches}$$
5. **Lateral Surface Area $L$:**
The lateral surface area is the sum of the areas of the four triangular faces.
Each triangle has base $3.5$ inches and slant height $l$ (unknown).
The area of one triangle is:
$$\frac{1}{2} \times 3.5 \times l = 1.75l$$
So,
$$L = 4 \times 1.75l = 7l$$
6. **Use Surface Area to Find Slant Height $l$:**
Given total surface area $S = 50.75$,
$$50.75 = 12.25 + 7l$$
Subtract base area:
$$50.75 - 12.25 = 7l$$
$$38.5 = 7l$$
Divide both sides by 7:
$$\cancel{7}l = \frac{38.5}{\cancel{7}}$$
$$l = 5.5 \text{ inches}$$
7. **Diagram Sketch:**
- Draw a square base with side length labeled $3.5$ inches.
- Draw four triangular faces meeting at the apex.
- Label the slant height $l = 5.5$ inches on one triangular face.
This completes the sketch and labeling of the right square pyramid with the given dimensions.