Question

The triangle below is equilateral. Find the length of side x in simplest radical form with a rational denominator.

Answer 1

hi

As the triangle is  equilateral, the height is also the median.

As the median cut the side in two equal halve, and one of this half is 9, then the side is 18.  

As the triangle is equilateral, every side is the same measure, so x = 18