If each interior angle of a regular polygon is 150°, then the number of sides in that polygon is :

If the difference between the interior and exterior angles of a regular polygon is 144°, then what is the number of sides of the polygon ?

If a, b and c are the sides of a right-angled triangle, where a > b > c, then what is the value of the expression (a + b + c) (a + b - c) (a - b + c) (a - b - c)?

If each of the dimensions of a rectangle is increased by 100%, then the area is increased by

The sides of an equilateral triangle are (2a – b) cm, (a + 3b) cm and (2a – 2b + 1) cm then the perimeter of the triangle is

The sides of a triangle are 5 cm, 12 cm and 13 cm. then its area is