Page 201 - ICSE Math 6

(c) All points in the exterior of circle A lies in the interior of circle B.

(d) Each secant of circle A is a tangent of circle B.
(e) Each tangent of circle A is a secant of circle B.
2. What name can you give to the centre of a circle that passes through the vertices of an equilateral
triangle?

(a) centroid (b) orthocentre
(c) either centroid or orthocentre (d) neither centroid nor orthocentre

Individual Activity

Objective: To draw a circle and understand its concept

Material required: A paper, circular object like CD, a pencil

Demonstration:
Step 1: Place any object having round shape, say a CD on a sheet of
paper.

Step 2: Trace around it to get a circular shape. This shape is called a
circle.

Step 3: Cut the circle neatly.

Step 4: Fold the circle in such a way that the two halves coincide.
Step 5: Open the fold and name the end points of the crease so
formed as A and B.

Step 6: Repeat steps 4 and 5 by folding the circle in a different way. A B
Name the new end points of the crease as C and D.

Step 7: Let AB and CD intersect at a point say O. D

Observation: Measure OA, OB, OC and OD. What do you observe? A O B
Inference: A circle is a set of points in a plane equidistant from a fixed point.
C

The fixed point is known as the centre and constant distance is the radius.

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