Answer:
third side = 4
Step-by-step explanation:
third side is hypoenuse as it is opposite to 90 degree.
using pythagoras theorem
(perpendicular)^2 + (base)^2 = (hypotenuse)^2
2^2 + (2 )^2 = hypotenuse^2
4 + 4*3 = hypotenuse^2
16 = hypotenuse^2
= hypotenuse
4 = hypotensue