Step-by-step explanation:
it's an equilateral triangle so all sides are equal
using Pythagorean theorem
2(√6) raised to the power of 2 = √6 raised to the power of 2 + x raised to the power of 2
2(√6) raised to the power of 2 is 12
√6 raised to the power of 2 is 6
therefore 12=6 + x
x = 12-6
x=6
