The base of a solid oblique pyramid is an equilateral triangle with an edge length of [tex]$s$[/tex] units.

Which expression represents the height of the triangular base of the pyramid?

A. [tex]\frac{s}{2} \sqrt{2}[/tex] units
B. [tex]\frac{s}{2} \sqrt{3}[/tex] units
C. [tex]s \sqrt{2}[/tex] units
D. [tex]5 \sqrt{3}[/tex] units



Answer :

To find the height of the triangular base of a pyramid when the base is an equilateral triangle with an edge length of [tex]\( s \)[/tex] units, we need to use the geometry of an equilateral triangle.

An equilateral triangle has three sides of equal length and all internal angles equal to [tex]\( 60^\circ \)[/tex]. The height [tex]\( h \)[/tex] of an equilateral triangle can be derived using basic trigonometry or geometric properties.

For an equilateral triangle, the height divides the triangle into two 30-60-90 right triangles. The relationship between the sides of a 30-60-90 triangle is well-established: the length of the side opposite the [tex]\( 30^\circ \)[/tex] angle is half the hypotenuse, and the length of the side opposite the [tex]\( 60^\circ \)[/tex] angle is [tex]\( \frac{\sqrt{3}}{2} \)[/tex] times the hypotenuse.

For our equilateral triangle with side length [tex]\( s \)[/tex]:
- The base of each 30-60-90 triangle (half the side length of the equilateral triangle) is [tex]\( \frac{s}{2} \)[/tex].
- The height [tex]\( h \)[/tex], opposite the [tex]\( 60^\circ \)[/tex] angle, is:
[tex]\[ h = \frac{\sqrt{3}}{2} \cdot s \][/tex]

Therefore, the height of the triangular base of the pyramid is:
[tex]\[ h = \frac{s \sqrt{3}}{2} \][/tex]

Given the possible choices:
[tex]\[ \frac{5}{2} \sqrt{2}, \quad \frac{5}{2} \sqrt{3}, \quad s \sqrt{2}, \quad 5 \sqrt{3} \][/tex]

The correct expression matches [tex]\(\frac{s \sqrt{3}}{2}\)[/tex]. To check against the numerical results:

1. [tex]\(\frac{5}{2} \sqrt{2} \approx 3.5355339059327378\)[/tex]
2. [tex]\(\frac{5}{2} \sqrt{3} \approx 4.330127018922193\)[/tex]
3. [tex]\(s \sqrt{2} \approx 1.4142135623730951\)[/tex] (assuming [tex]\(s = 1\)[/tex])
4. [tex]\(5 \sqrt{3} \approx 8.660254037844386\)[/tex]
5. [tex]\(\frac{s \sqrt{3}}{2} \approx 0.8660254037844386\)[/tex] (assuming [tex]\(s = 1\)[/tex])

The correct height of the triangular base, as derived, is approximately [tex]\( 0.8660254037844386 \)[/tex], which corresponds to [tex]\(\frac{s \sqrt{3}}{2}\)[/tex].

Thus, none of the provided choices directly represent [tex]\(\frac{s \sqrt{3}}{2}\)[/tex] as the height.

This suggests that the correct representation of the height of the triangular base of the pyramid is [tex]\(\frac{s \sqrt{3}}{2}\)[/tex], however, it is noticeable that this representation was not presented among the discussed options explicitly; hence, among the given choices, selection none makes more sense logically unless given the correct equation correctly.