Construct an equilateral triangle whose perimeter is 15 cm?

steps of construction:

1. let us draw a straight line PQ=15 cm.

2. at P draw an angle RPQ=60 deg, at Q draw an angle SQP=60 deg.

3. now we will draw the angle bisectors of ∠RPQ and ∠SQP. let it intersect at point A.

4. draw the perpendicular bisector of PA and QA. let it intersect PQ at B and C respectively.

5. join AB and AC.

thus ABC is the required triangle.

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