Slant Height Explained
1. The problem asks to explain the concept of slant height in a right square pyramid.
2. A right square pyramid has a square base and an apex directly above the center of the base, forming perpendicular height $h$.
3. The slant height $s$ is the length of the line segment from the apex to the midpoint of any side of the square base along the triangular face.
4. To find $s$, consider the right triangle formed by:
- the pyramid height $h$
- half the base side length $\frac{b}{2}$
- the slant height $s$ as the hypotenuse
5. Using the Pythagorean theorem:
$$s^2 = h^2 + \left(\frac{b}{2}\right)^2$$
$$\Rightarrow s = \sqrt{h^2 + \left(\frac{b}{2}\right)^2}$$
6. For example, if $h=15$ cm and $b=10$ cm:
$$s = \sqrt{15^2 + 5^2} = \sqrt{225 + 25} = \sqrt{250} = 5\sqrt{10}$$ cm
7. The slant height $s$ serves as the height of each triangular face of the pyramid.
8. This height is essential for calculating the area of one triangular face:
$$\text{Area} = \frac{1}{2} \times b \times s$$
9. Finally, knowing all triangular face areas plus base area allows calculation of total surface area.
This explanation details the geometric meaning and calculation of slant height.