THis equals the number of permutations of 4 from 6.
= 6P4 = 6! / (6 - 4)! = 6! / 2! = 720/2 = 360 answer
ANSWER

EXPLANATION
Since the altitude, |GJ| bisects the base of the triangle, it follows that, the triangle is an isosceles triangle.
This implies that,.

In terms of x, we have the equation.

We now group like terms to obtain,

This implies that,

Let us divide through by 2 to get,

We can see from the diagram that,

We substitute x=5 to get,

This simplifies to,

The answer is 25% because 20/50=0.25x100=25%