ΔABC is similar to ΔDEF. Length of AB is 18 cm and  length of the corresponding side  DE is 10 cm. What is the ratio  of Perimeter of ΔABC : Perimeter of ΔDEF?

Find the second diagonal of a rhombus when it’s first diagonal length is 12 cm and its side is 10 cm?

Triangle PQR is such that PQ=9 cm, QR=6 cm, PR=7.5 cm and triangle PQR is similar to triangle XYZ. If XY=18 cm, find the value of YZ.

In △PQR, ∠P = 90°. S and T are the mid points of sides PR and PQ, respectively. What is the value of RQ²/(QS²+ RT²)?

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 

If the area of a circle is 9π sq.cm then it circumference is

If radius of a sphere is decreased by 48%, then by what percent does its surface area decrease?

ABCD is a rhombus whose one angle is 60°.Find the ratio of the lengths of its diagonal?