Answer:
9.24 m to 2 DP's.
Explanation:
Consider the right triangle formed from a side , altitude and 1/2 the base.
By pythagoras:
x^2 = 8^2 + (0.5x)^2 where x is the length of each side.
x^2 - 0.25x^2 = 64
0.75x^2 = 64
x^2 = 64/0.75 = 85.3333.
x = 9.2376 m.