Question

AB = 6, BC = 8 , AC =

2√7
10
√(76)

Answer 1

Do you know how to use Pythagoras Theorem?

Answer 2

Essentially it's a theorem stating that where a, b and c are thee sides in a triangle, \[a^2 + b^2 = c^2\]

Answer 3

This law can only be applied to right angled triangles. If the triangle that you have given information for, is not a right angled triangle, it cannot be solved, so I am assuming it is.