Ex 11.1, 5 Construct an equilateral triangle, given its side and justify the construction.Let’s assume side of equilateral triangle is 5.5 cm
In an equilateral triangle, all sides are equal
So, our triangle looks like
Let’s construct it
Steps of construction
1. Draw a line segment AB of length 5.5 cm
2. Taking 5.5 cm as radius,
and A as center,
draw an arc.
3. Taking 5.5 cm as radius,
and B as center,
draw another arc.
Let C be the point where the two arcs intersect
Join AC and BC
and label the sides
Thus, Δ ABC is the required equilateral triangle
Justification
By construction,
AB = AC = BC
Since all sides are equal
∴ ∆ABC is an equilateral triangle.
Thus, the Construction is justified.
(Radius of equal arcs)

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Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.