If 2s = a + b + c, then what is s² + (s- a)(s-b) + (s -b)(s-c) + (s - c)(s - a) equal to?

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)?

The area of a circle is 40π² . The area of a square with sides equal to radius of the circle is

A solid cube is cut into two cuboids of equal volume. What is the ratio of total surface area of the given cube to that of one of the cuboids ?

If the area of a square is equal to the area of an equilateral triangle, the ratio of the side of the square and the side of the equilateral triangle is

If the perimeter and the area of a circle are numerically equal, then the radius of the circle is