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?

PQR is a right angled triangle in which PQ = QR . If the hypotenuse of the triangle is 20 cm , then what is the area ( in cm ) of the triangle PQR ?

Triangle PQR is inscribed in the circle whose radius is 14 cm . If PQ is the diameter of the circle and PR =10 cm , then what is the area of the triangle ? 

What can be the maximum number of common tangent, which can be drawn to two non-intersecting circles? 

Triangle PQR is inscribed in a circle such that P, Q and R lies on the circumference . If PQ is the diameter of the circle and ∠PQR = 40 ° , then what is the value ( in degrees ) of ∠QPR ?

PAB and PCD are two secants to a circle . If PA 10 cm , AB = 12 cm and PC = 11 cm , then what is the value ( in cm ) of PD ?

In the given figure, SX is tangent. SX = OX = OR. If QX=3 cm and PQ = 9 cm. then what is the value (in cm) of OS?

In the given figure ABC is an equilateral triangle. Two circles of radius 4 cm and 12 cm are inscribed in the triangle. What is the side (in cm) of an equilateral triangle?