Question

Sundial is used to measure time in some monuments. Explain the basic principle used to construct a sundial.

Answer 1

it's a sun clock.it uses sun to show time

Answer 2

Sundial is a special instrument that is used to measure time by shadow casted by the gnomon (a right triangular piece used as a caster) whe the sun's rays hit on it. At first the apparent readings are taken and are marked precisely on the dial. Afterwards, the sundial is ready to be used.

It works on the principle that the shadow casted by the sun in its different apparent positions.