A and B are the centres of two circles with radii 11 cm and 6 cm respectively. A common tangent touches these circles at P & Q respectively. If AB = 13 cm, then the length of PQ is 

Let G be the centroid of the equilateral triangle ABC of perimeter 24 cm. Then the length of AG is

Let two chords AB and AC of the larger circle touch the smaller circle having same centre at X and Y. Then XY = ?

A chord of a circle is equal to its radius. The angle subtended by this chord at a point on the circumference is

ΔABC is similar to ΔDEF. If area of ΔABC is 9 sq.m. and area of ΔDEF is 16 sq.cm. and BC = 2.1 m. Then the length of EF will be 

If a+ 1/a = -2 then the value of

a¹⁰⁰⁰+a^-1000 is