Draw $\triangle ABC$ with $AB = 5$ cm, $\angle A = 70^\circ$ and $\angle B = 60^\circ$.
Draw the circumcircle of $\triangle ABC$. Is the centre inside or outside the triangle?                                            [Page No. 98]

Construction steps:

1. Draw segment AB = 5 cm.

2. At A, construct ∠A = 70°; at B, construct ∠B = 60°. Let the two rays meet at C.

3. ∠C = 180° - (70° + 60°) = 50°.

4. Draw perpendicular bisectors of any two sides (say AB and BC); they meet at point O.

5. With O as centre and OA as radius, draw the circumcircle. It passes through A, B and C.

Since all three angles (70°, 60°, 50°) are less than 90°, ΔABC is an acute-angled triangle.
Therefore, the circumcentre O lies inside the triangle.