The figure below has been obtained by folding a rectangle. The total ...
Folded part as shown in the first figure is a right angled triangle.
The two perpendicular sides of the right triangle measure 6m each. So, the triangle is a right isosceles triangle.
When unfolded the folded area becomes a square as shown in the following figure.
The side of the square will be the width of the larger rectangle and is therefore, 6m.
Area of the square = 6 * 6 = 36 sq.m
When folded, only the area of the right triangle gets counted. However, when unfolded the area of square gets counted.
The square comprises of two congruent right triangles.
In essence, when folded only half a square is counted. When unfolded the entire square gets counted.
The area of the rectangle when unfolded = area of the rectangle when folded + area of half a square.
So area after unfolding = 144 + 18 = 162 sq.m.