A rectangular piece of paper was folded to form the shape shown. What was the area of the piece of paper before it was folded?

In triangle ABC, as shown in figure, find the area of triangle ADC.

A wire in the form of a rectangle $23.4 cm$ long and $19.7 cm$ wide is reshaped and bent into a square. Find the area of the square formed.

A square floor of side 30 m is to be tiled with right triangles of sides 3 m, 4 m and 5 m. How many tiles will be needed to cover the floor?

 The inner and outer radii of a cylindrical pipe are $5 cm$ and $5.5 cm$ respectively. Find the area of the cross-section of the pipe.

The length of a rectangle is $12 m$ and the length of its diagonal is $15 m$. Find the area of the rectangle.

The cost of painting a triangular region of wall was $₹132.48$. If the base of the triangle was $2.4 m$, find its altitude. The rate of painting is $₹120 per 5 m^2$.