Page 68 - Maths Class 06

10. If the circum ference of a circle is 132 cm, what is the length of its diam eter?

11. Draw a circle. Mark:
(a) three points A B C, , in its interior.
(b) three points P Q R, , on the circle.
(c) three points X Y Z, , in its exterior.

At a Glance

l In geometry, point, line, line segment and ray are four undefined terms.
l A part of a line with definite length is called a line segment. A line segment has two end-points.
l A point marked on a line divides the line into two rays. A ray has one end-point.

l Two lines are said to be intersecting lines, if they have a common point.
l Two lines lying in a plane are said to be parallel, if they are not intersecting lines.
l Two rays with a common end-point form an angle.

l A closed figure made up of three line segments is called a triangle. A triangle has three sides and three
angles.

l A median of a triangle is a line segment that joins a vertex to the mid-point of the opposite side of the
triangle.
l Three medians of a triangle meet at a point.

l A closed figure made up of four line segments is called a quadrilateral. The sum of the interior angles
of a quadrilateral is 360°.

l A circle is the collection of all those points in a plane whose distance from a fixed point remains
constant.

l A line segment joining the centre and a point of the circle is called a radius.

l A line segment joining any two points of a circle is called a chord.
l A chord passing through the centre of a circle is called diameter.
l When a circular region is divided into two pieces, each piece is called a segment.

l A region enclosed an arc and a pair of radii of a circle is called the sector of the circle.

Multiple Choice Questions

Tick (3) the correct answer:
1. The vertex of an angle lies:

(a) in its interior (b) in its exterior
(c) on the angle (d) None of these
2. If the radius of a circle is equal to 5 cm, then the longest chord it can have is of length:
(a) 5 cm (b) 8 cm (c) 10 cm (d) 20 cm

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