The sum of all interior angles of a regular polygon is 1080∘. What is the measure of each of its interior angles ?
(a) 135∘ (b) 120∘ (c) 156∘ (d) 144∘
If a regular polygon has 12 sides, then the measure of its each interior angle is ___.
If each interior angle of a regular polygon measure 135∘, then it has __ sides.