Answer:
z=4√5
Explanation:
use the Pythagorean theorem to set up a system of equations. a^2 + b^2 = c^2
16+4= 20
20^2 = x^2 + z^2 400=x^2 + z^2 x^2=400-z^2
z^2 = 4^2 + y^2 z^2 = 16 + y^2
x^2 = 16^2 + y^2 x^2 = 256 + y^2 y^2=x^2-256
z^2=16+x^2-256
z^2=16+400-z^2-256
z^2=160-z^2
2z^2=160
z^2=80
z= √80 =4√5