Measuring a Canopy

Things required:
Chalk powder to mark the shadow and a measuring tape.

A canopy is the cover formed by leafy upper branches of a tree. Can we measure the canopy area of a tree? If you thought you had to climb up to the tip of the branches, here is a way to find the area without actually climbing up there.

During mid day, 12 noon, when the Sun is overhead, draw along the border of the shadow of a tree using chalk powder. Mark points A, B, C …along the line.
Let the base of the tree be O.

Measure distances OA, OB, and OC etc.

Find the area of different triangles and add them up. This will give the approximate canopy area of the tree. (Take the help of your Math teacher or your seniors at school, if required)

Note:
1. The Sun has to be overhead. The Sun in any other direction will not give the exact canopy area.
2. Area of a triangle is

where s= (a+b+c)/2; a, b, c are the sides of a triangle.

Why are not all trees of the same height? Why do different trees have varying canopies?
Trees attain different heights and place their canopies differently, to avoid competition for sunlight.