Question

Describe the graphical method to find the area of an irregularly shaped plane figure.

Answer 1

To find the area of an irregularly shaped plane figure, we have to use graph paper.

1. Place a piece of paper with an irregular shape on a graph paper and draw its outline.
2. To find the area enclosed by the outline, count the number of squares inside it (M).
3. You will find that some squares lie partially inside the outline.
4. Count a square only if half (p) or more of it (N) lies inside the outline.
5. Finally count the number of squares, that are less than half. Let it be

For the shape in figure we have the following:

M = 50
N = 7
P = 4
Q = 4

Now, the approximate area of the can be calculated using the following formula.

Area of the leaf = `"M"+(3/4) "N" + (1/2) "P"+1/4 "Q sq.cm"`
= 52 + 5.25 = 58.25 sq.mm = 0.5825 sq.cm