Question

you are helping install a light pole in a parking lost. when the pole is positioned properly, it is perpendicular to the pavement. How can you check that the pole is perpendicular using a tape measure

Answer 1

Measure out horizontally 3.
Measure up vertically 4.
The distance between those two points should be 5.
Repeat in 4 directions around the pole.

3^2 + 4^2 = 5^2.
(this is a 90° right angle triangle)