Q. 3. A picture is painted on a cardboard long and wide such that there is a margin of along each of its sides. Find the total area of the margin.
It is given that cardboard is long and wide such that there is a margin of along each of its sides
It is clear that it is rectangular shaped with
We know that the area of the rectangle is
-(i)
Now, the length and breadth of cardboard without margin is
Area of cardboard without margin is
-(ii)
Area of margin is (i) - (ii)
Therefore, the area of margin is