The question asks to find the surface area of a regular square pyramid, with the following information provided in the diagram:

• The base side length ($s$) is $2.5$ cm.
• The slant height ($l$) is $5$ cm.

The surface area ($A$) of a square pyramid is given by the formula: $A = s^2 + 2 \cdot s \cdot l$ Where:

• $s^2$ is the area of the base (a square),
• $2 \cdot s \cdot l$ is the area of the four triangular faces.

Let's calculate the surface area using this formula.

Given:

• $s = 2.5 \, \text{cm}$
• $l = 5 \, \text{cm}$

I'll compute it now.The surface area of the regular square pyramid is $31.25 \, \text{cm}^2$.

Would you like more details on this calculation or have any other questions? Here are a few related questions to consider:

1. How would the formula change if the base were a rectangle instead of a square?
2. How do you calculate the height of the pyramid if only the slant height is known?
3. How would the surface area change if the slant height were doubled?
4. How do you calculate the volume of this square pyramid?
5. What is the lateral surface area, and how does it differ from the total surface area?

Tip: Always check that the units for all dimensions match when applying surface area or volume formulas!