Answer:
2√(5)
Step-by-step explanation:
Since it's stated that thegiven is right triangle :
The square length of hypotenus (the side lenght that sees 90 degrees) is equal to sum of square length of side lengths
2^2 + 4^2 = x^2
4 + 16 = x^2
20 = x^2 and x = 2√(5)
