Given :
A triangle whose sides are 5 cm, 4.5 cm and 7 cm.
To construct : Circumcircle of this triangle.
Steps of construction:
(1) Let triangle be ABC, whose sides AB = 5 cm, AC = 4.5 cm and BC = 7 cm.
(2) From point A radius 4.6 cm drawn an arc also from point B and radius 7 cm draw another arc that intersects the first arc at C.
(3) Join AC and BC. In this way we get the ΔABC. Since it is an obtuse triangle. Thus its circumcentre will lie outside the circle.
(4) Draw the perpendicular bisectors of sides AB and BC to intersect each other at O. Which is the circumcentre of the ΔABC and is outside the triangle.
(5) Join A to O taking O as center and with radius equal to AO draw a circle which passes through three vertices of ΔABC.
This is the circumcircle of ΔABC.
