The perimeter of a triangular field is 450 m and its sides are in the ratio 13 : 12 : 5. Then the area of the triangle is ______

If a triangle has a base of 8 inches and a height of 4.5 inches, then its area is ______ sq inches.

The area of an equilateral triangle is 81 $\sqrt{3}$  sq cm . Find its perimeter.

 $cm^2$  

The area of the quadrilateral ABCD is _____ cm

The area of the circle that can be inscribed in a square of side 6 cm, is _____ sq cm

The radii of two circles are 4 cm and 3 cm respectively. The diameter of the circle having area equal to the sum of the areas of the two circles = ______ cm

In circle O, the radius is 4, and the measure of angle AOB is 120 degrees. Find the length of minor arc AB to the nearest integer. 

Find the area of the shaded part given AB is the diameter of the circle with centre O and OA = 7 cm

Find the area of the shaded part given that the diameter of the inner circle is 21 cm and the uniform width of the shaded part is 10.5 cm.