Question

A triangle has sides with lengths of 8 kilometers, 13 kilometers, and 16

Answer 1

No, It’s not a right triangle.
We can prove by using Pythagoras theorem
Let the longest length be hypotenuse and shortest length be base now,

h^2=p^2+b^2
16^2=13^2+8^2
256=169+64
246=233


Hence it is not equal with hypotenuse
In right triangle the sum of the squares of two short sides should be equal to hypotenuse