Construction of the Circumcentre of a Triangle, Incircle of a Triangle
1. Draw a triangle ABC, where AB = 8 cm, BC = 6 cm and ∠B = 70º and locate its circumcentre and draw the circumcircle.
2. Construct the right triangle PQR whose perpendicular sides are 4.5 cm and 6 cm. Also locate its circumcentre and draw the circumcircle.
3. Construct ΔABC with AB = 5 cm ∠B = 100º and BC = 6 cm. Also locate its circumcentre draw circumcircle.
4. Construct an isosceles triangle PQR where PQ= PR and ∠Q = 500, QR = 7cm. Also draw its circumcircle.
5. Draw an equilateral triangle of side 6.5 cm and locate its incentre. Also draw the incircle.
6. Draw a right triangle whose hypotenuse is 10 cm and one of the legs is 8 cm. Locate its incentre and also draw the incircle.
7. Draw ΔABC given AB = 9 cm, ∠CAB = 115° and ΔABC = 40° . Locatge its incentre and also draw the incircle. (Note: You can check from the above examples that the incentre of any triangle is always in its interior).
8. Construct ΔABC in which AB = BC = 6cm and ∠B = 80° . Locate its incentre and draw the incircle.