Given that (a²+b²)=60, then find the value of (a+b)²+(a–b)².

The exterior angle of a regular polygon is one-third of its interior angle, the number of sides of the polygon is -

If AD, BE and CF are medians of ∆ABC, then which one of the following statements is correct? 

A solid sphere of diameter 7 cm is cut into two equal halves. What will be the increase (in cm.²) in the total surface area?

A field in the shape of a trapezium whose parallel sides are 200 meter and 400-meter-long, whereas each of other two sides is 260 meter long. What is the area (in m²) of the field?

If the numerical value of the perimeter of an equilateral triangle is √3 times the area of it, then the length of each side of the triangle is:

PQRS is square whose side is 20 cm. By joining opposite vertices of PQRS are get four triangles. What is the sum of the perimeters of the four triangles?

The diagonals AC and BD of a cyclic quadrilateral ABCD intersect each other at the point P. Then, it is always true that