PQRS is square whose side is 20 cm. By joining opposite vertices of PQRS are get four triangles. What is the sum of the perimeters of the four triangles?

X and Y are centres of circles of radius 9 cm. and 2 cm respectively XY=17 cm. Z is the centre of a circle of radius r cm which touches the above circles externally. Given that - ∠xzy = 90^o the value of r is -

In ΔABC, ∠C=90° and D is a point on CB such that AD is the bisector of ∠A. If AC=5 cm and BC=12 cm, then what is the length of AD?

If there are four lines in a plane, then what cannot be the number of points of intersection of these lines? 

If the area of a circle, inscribed in a equilateral triangle is 4 π cm², then what is the area of the triangle?

Two medians AD and BE of ∆ABC intersect G at right angle. If AD = 9 cm and BE = 6 cm, then the length of BD ( in cm ) is

In △ABC, M and N are the points on side BC such that AM ⊥ BC, AN is the bisector of ∠A, and M lies between B and N. If ∠B = 68°, and ∠C=26°, then the measure of ∠MAN is:

If the ratio of the measurements of the three angles of a triangle is 2: 3: 4, then the measurement of its largest angle is.