Answer:A
Step-by-step explanation:
from Pythagoras principle we get:
Hypotenuse=√(4^2+2^2)
Hypotenuse=√(4x4+2x2)
Hypotenuse=√(16+4)
Hypotenuse=√(20)
Hypotenuse=√(4x5)
Hypotenuse=√4 x √5
Hypotenuse=2 x √5
Hypotenuse=2√5
Perimeter=4 x hypotenuse
Perimeter=4 x 2√5
Perimeter=8√5
