In a quadrilateral ABCD, E is a point in the interior of the quadrilateral such that DE and CE are the bisectors of ∠D and ∠C, respectively. If ∠B = 82° and ∠DEC = 80°, then ∠A = ?

A container in the shape of a frustum of a cone having diameters of its two circular faces as 35 cm. and 30 cm and vertical height 14 cm. is completely filled with oil. If each cm3 of oil has mass 1.2g, then find the cost of oil in the container if its costs Rs. 40 per kg.

Triangle PQR is inscribed in the circle whose radius is 14 cm . If PQ is the diameter of the circle and PR =10 cm , then what is the area of the triangle ? 

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?

The lengths of the lengths placed on the sides of a point inside an equilateral triangle are 6 cm, 8 cm and 10 cm. What is the area of the triangle?

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:

ABCD is a trapezium in which AB is parallel to CD and AB = 4 ( CD ) . The diagonals of the trapezium intersects at O. what is the ratio of area of triangle DCO to the area of the triangle ABO ?

In a ∆ABC ∠A : ∠B : ∠C  = 2 : 3 : 4 . A line CD drawn || to AB, then the ∠ACD is: