What is the length of the altitude of the equilateral triangle below?

B. 3 √3

The shortcuts for a 30 60 90 triangle is that the:

Hypotenuse is 2 times the short leg

The long leg is √3 times the short leg.

Making it 3 √3

Another way is by the Pythagorean Theorem.

a^2+b^2=c^2

3^2+b^2=6^2

9+b^2=36

Subtract 9 from both sides

b^2=27

Square root both sides

b=5.2 or the √27

√27 can be simplified more

An equation that equals to 27 that has a perfect square is 9*3

√9* √3

The perfect square of 9 equals to 3

So 3 √3