Let ΔABC ∼ Δ PQR and ar(∆ABC)/ar(∆PQR) =4/25. If AB = 12 cm, BC = 8 cm and AC = 9 cm, then QR is equal to:

For an equilateral triangle, the ratio of the in-radius and the outer- radius is

PK is the median and M is a centroid of triangle PQR. If PK is 15 cm, then find length of PM?

In a circle with centre O, AB is the diameter. P and Q are two points on the circle on the same side of the diameter AB. AQ and BP intersect at C. If ∠POQ = 54°, then the measure of ∠PCA is:

A secant PAB is drawn from an external point P to the circle with centre O, intersecting it at A and B. If OP = 17 cm, PA = 12 cm and PB = 22.5 cm, then the radius of the circle is:

AC is a chord of circle whose centre is at O. If B is any point on the arc AC and ∠OCA=20⁰ , then the magnitude of ∠ABC is

On increasing the radius of circle by 1 cm, its area is increased by 44 cm² .The original radius of the circle is -

If the circumradius of an equilateral triangle be 10 cm, then the measure of its in-radius is