Please answer the question and give an explanation. Will give brainliest.

Step-by-step explanation:
By Pythagoras' Theorem, z^2 + (2.7)^2 = (4.2)^2.
This means that z^2 = (4.2)^2 - (2.7)^2 = 10.35.
So z = 3.2 (1 d.p.)
Step-by-step explanation:
x=4.2
y=2.7
z=x
(×+y=×
(4.2+2.7=×)
×=6.9