Question

Using ruler and compasses only, construct and equilateral triangle with side 4.5 cm. Draw a circumcircle of this triangle and measure its radius. 

Answer 1

Steps of construction: 

(i) Draw line AB= 4.5 cm 

(ii) At B 1 draw an arc making an angle of 60" • with AB and Ieng th BC = 4. 5 cm. 

(iii) On the arc cut AC = 4.5 cm. 

(iv) Join AC. 

(v) Draw perpendicular bisectors of AB and BC, which meet at O. 

(vi) With O as centre and radius equal to the distance between O and the vertex of the triangle 1 draw a cricle to pass through alI the three vertices of the triangle. 

(vii) The drawn circle is the required circle with radius= 2.6 cm