PQR is an equilateral triangle whose side is 10 cm . What is the value (in cm) of the inradius of triangle PQR ?

If the circumcenter of the triangle lies outside it, then the triangle is 

If the angles of a triangle are in the ratio of 1:4:7, then find the ratio of the greatest angle to the smallest angle.

ΔABC and ΔDBC are on the same base BC but on opposite sides of it. AD and BC intersect each other O. If AO=a cm, DO=b cm and the area of ΔABC= x cm², then what is the area (in cm²) of ΔDBC?

P and Q are center of two circles with radii 9 cm and 2 cm respectively, where PQ = 17 cm, R is the center of another circle of radius x cm, which touches each of the above two circles externally. If ∠PRQ = 90 °, then the value of x is 

A circle and a rectangle have the same perimeter. The sides of the rectangle are 18 cm and 26 cm. The area of the circle is:

G is the centroid of a triangle ABC, and the median is AD, the ratio of AD and GA is

A container in the shape of a frustum of a cone having diameters of its two circular faces as 35 cm. and 30 cm and vertical height 14 cm. is completely filled with oil. If each cm3 of oil has mass 1.2g, then find the cost of oil in the container if its costs Rs. 40 per kg.