#### Using ruler and compasses only, draw an equilateral triangle of side 5 cm and draw its inscribed circle. Measure the radius of the circle.

**Solution:**

#### The bisectors of angles A and B of a scalene triangle ABC meet at O.

(i) What is the point O called?

(ii) OR and OQ is drawn a perpendicular to AB and CA respectively. What is the relation between OR and OQ?

(iii) What is the relation between ∠ACO and ∠BCO?

**Solution:**

**More Solutions:**

- The length of the tangent to a circle is 24 cm and the distance of Q.
- If the angle between two radii of a circle is 130°.
- If tangents PA and PB from an exterior point P to a circle.
- At one end A of a diameter AB of a circle of radius 5 cm.
- AB is a chord of the circle such that ∠ACB = 50°.
- PA and PB are tangents to a circle with centre O.