10 POINTS PLEASE HELP ASAP!!! What is the length of the altitude of the equilateral triangle below?

Step-by-step explanation:
Hey there!
Looking on figure we find that triangle ABC is a Right angled triangle.
Taking reference angle as C, we get;
Perpendicular (p) = a
Base(b) = 5
And hypotenuse (h)= 10
Now;
Using Pythagoras relation, we get;
[tex]p = \sqrt{ {h}^{2} - {b}^{2} } [/tex]
Put all values.
[tex]a = \sqrt{ {10}^{2} - {5}^{2} } [/tex]
[tex]a = \sqrt{100 - 25} [/tex]
[tex]a = \sqrt{75} [/tex]
[tex]a = 5 \sqrt{3} [/tex]
Therefore, answer is Option E.
Hope it helps..