Question

how to draw an equilateral triangle with side 7.5 cm

Answer 1

DIAGRAM:

$\setlength{\unitlength}{1cm}\begin{picture}(0,0) \thicklines \put(0,0){\line(1,0){2}}\put(0,0){\line( - 1, 0){2}}\put( - 2,0){\line(2, 3){2}}\put( 2,0){\line( - 2, 3){2}} \qbezier( -0.25, 3.45)(1, 1)(0.5,2 )\qbezier( - 0.5, 2.45)(1, 4)(0.5, 3) \put(-2.4,0){ \bf A }\put(2.05,0){ \bf B }\put(-0.5,3){ \bf C } \multiput(-2,2)(2.8,0){2}{ \bf 7.5 \ cm }\put( - 0.5, - 0.35){ \bf 7.5\ cm }\end{picture}$

CONSTRUCTION:

• Using ruler draw a line AB of 7.5 cm.

• Taking A as a centre draw an arc at 7.5 cm with the help of a compass.

• Again without changing the measurement draw an arc with B as a centre.

• Mark C in the place where two arcs intersect.

• Join AC and BC.

• We will get the triangle ABC which is an equilateral triangle of sides AB, BC, CA. [ where AB = BC = CA = 7.5 cm ]

• Also we can verify using protractor that all the angles will be equal as 60°.

• As we are not asked to locate the centriod of the triangle two arcs is enough.

Answer 2

Construction:-

1. Draw a line AB = 7.5 cm

2. with A as centre and length= 7.5 cm draw an arc

3. with B as centre and length = 7.5 cm draw another arc to cut the arc drawn in step 2 at C

4. Join AC and BC .ABC is the required triangle.