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Triangle
- It is a shape.
- It is bounded.
- It has 3 sides.
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Activity
Three ants started their journey from point A of given triangles.
Each of them travelled from A → B, B → C, and C → A.
Ant A
15
cm total
Ant B
12
cm total
Ant C
18
cm total
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Conclusion
The distance travelled by ants A, B, and C around their triangles is
actually the perimeter of their respective triangles.
Definition
A path around any shape is called its perimeter.
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Length of Wire / Rope Needed to Fence
Once (1 time)
\[L = P\]
Twice (2 times)
\[L = 2P\]
Thrice (3 times)
\[L = 3P\]
General Formula — n times
\[\therefore \; L = nP\]
where P = Perimeter of the triangle |
n = number of times the shape is fenced
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Total Cost of Fencing
If R is the rate of wire per unit length, then:
\[\therefore \; T.C = R \times L\]
T.C = Total Cost
R = Rate per unit
L = Total length of wire