**Basic Geometrical Ideas**

## Exercise – 4.6

**Ex 4.6 Question 1.**

**From the figure, identify:**

**(a) the centre of circle**

**(b) three radii**

**(c) a diameter**

**(d) a chord**

**(e) two points in the interior**

**(f) a point in the exterior**

**(g) a sector**

**(h) a segment**

**Solution:**

(a) O is the centre of the circle.

(b) Three radii = OA, OB, OC

(c) A diameter = AC

(d) A chord = ED

(e) Two points in the interior = O, and P

(f) A point in the exterior = Q

(g) A sector = AOB

(h) A segment = ED

**Ex 4.6 Question 2.**

**(a) Is every diameter of a circle also a chord?**

**(b) Is every chord of a circle also a diameter?**

**Solution:**

**(a) **Yes, every diameter of a circle is also a chord. Diameter is also called as the longest chord.

(b) No, every chord of a circle is not a diameter.

**Ex 4.6 Question 3.**

**Draw any circle and mark**

**(a) it’s centre**

**(b) a radius**

**(c) a diameter**

**(d) a sector**

**(e) a segment**

**(f) a point in its interior**

**(g) a point in its exterior**

**(h) an arc**

**Solution:**

(a) Centre = O.

(b) The radius = O

(c) A diameter = AC

(d) A sector = OAB

(e) A segment =ED

(f) A point in its interior = O

(g) A point in its exterior = Q

(h) An arc = AB

**Ex 4.6 Question 4.**

**Say true or false:**

**(a) Two diameters of a circle will necessarily intersect.**

**(b) The centre of a circle is always in its interior.**

**Solutions:**

(a) True.

(b) True.