The length of the common chord of two circles of radii 30 cm and 40 cm whose centers are 50 cm apart is (in cm) 

If the perimeter of an equilateral triangle is 30 meters, what is its height?

The difference between the circumferences of two circles is 110 cm and the radius of the smaller circle is 14 cm. what is the radius of the larger circle?

 If $$ {x=7-4\sqrt{3}}$$ find the value of $$ {\sqrt{x}+{1\over {\sqrt{x}}}}$$.

If the perimeter of a rhombus is 80 cm and one of its diagonals is 24 cm, then what is the are (in cm²) of the rhombus?

If two complimentary angles are in the ratio of 4:5, find the greater angle.

In a circle, PQ is diameter, RS is chord of length equal to radius of circle. PR and QS when produced intersect at point T. Find the ∠PTQ?

ABC is an isosceles triangle with AB = AC, A circle through B touching AC at the middle point of Q, intersects AB at P. Then AP : AB is :