QUIZ ON PARTS OF A CIRCLE

Problem 1 :

________ is the line segment joining the center of a circle to any point of the circle.

Solution :

·  All the points on the circle are at equal distances from the center of the circle, and this equal distance is called as radius of the circle.

· Hence, a line segment joining the center of a circle to any point of the circle is called radius.

Problem 2 :

________ is the longest chord.

Solution :

· Chord is a line segment connecting two points on a curve.

· Draw a straight line between these two points on the edge of the circle. This line is called a chord.

· When the chord passes through the center of a circle it is called the diameter.

· Diameter is the longest chord of a circle.

Problem 3 :

Perimeter of the circle is its ______.

Solution :

·  The circumference is the distance around a circle.

· Circumference of a circle = 2πr or πd

· Perimeter of the circle is called its circumference.

Problem 4 :

A _______ of a circle is a line segment joining any two points on the circle passing through origin.

Solution :

· A chord is a line segment with both endpoints on the same circle.

·  The largest possible chord is always a diameter.

· The line segment joining any two points on the circle passing through origin is called a chord of the circle.

Problem 5 :

The circumference of a circle with radius 7 cm is ______.

Solution :

Given, radius = 7 cm

Circumference of the circle = 2πr

= 2 × 22/7 × 7

= 44 cm

So, circumference of the circle is 44 cm.

Problem 6 :

A _____ is a line segment whose end points lie on the circle.

Solution :

· Any line segment that joins two points present on the circumference of the circle is called a chord.

· A chord of a circle is a straight line segment whose endpoints both lie on the circle.

Problem 7 :

Half of the semicircle is called _____.

Solution :

Half of the semicircle is called

     Half of the semicircle is called quadrant.

Problem 8 :

The circumference of a circle is ____.

Solution :

Perimeter of circle = circumference -- (1)

Perimeter = boundary -- (2)

From (1) & (2)

Circumference = boundary

The circumference of a circle is called boundary.

Problem 9 :

Draw a circle of radius 4.2 cm. Draw its longest chord and measure it.

Solution :

Longest chord of a circle will be diameter. So, longest chord of circle is 8.4 cm.

Problem 10 :

If two circles of center O and C with radii 3 cm and 4.5 cm touch externally. What is the distance between their centers?

Solution :

The distance between their centers = r₁ + r₂

= 3 + 4.5

= 7.5 cm

Problem 11 :

If length of a chord passing through the center of the circle is 12 cm. what is the radius of the circle?

Solution :

Diameter of the circle = 12 cm

r = 12/2

r = 6 cm

So, the radius of circle is 6 cm.

Problem 12 :

Draw a circle having diameter 9.6 cm. measure the radius.

Solution :

diameter of a circle = 9.6 cm

Radius = d/2

= 9.6/2

= 4.8 cm

Problem 13 :

How many circles can be drawn to pass through two given points?

Solution :

Infinite number of circles can be drawn from two points.

Problem 14 :

Points A, B, C and D are four points on the circle with center O.

Here are six words that are used with circles.

Arc    Diameter     Chord      Tangent   

Circumference     Radius

Choose the correct word to describe each line below.

(a) The straight line AC is a ............................................... of the circle.

(b) The straight line OD is a ............................................... of the circle.

(c) The straight line BC is a ............................................... of the circle.

(d) Draw a sector of the circle below.

Solution :

(a) AC is the line which connects two points on the boundary of the circle and it passes through the center. The straight line AC is a diameter of the circle.

(b) OD is the line which connects a position from center and one of the point on the boundary. So, the straight line OD is a radius of the circle.

(c) BC is the line which connects two points on the boundary and does not pass through the center of the circle. The straight line BC is a chord of the circle.

(d) sector of the circle :

Problem 15 :

Using the diagram below, give an example of each circle part.

Solution :

a) Center - P is the center

b) Radius - PL, PM and PN are radii

c) Diameter - NL is the diameter

d) Chord - LM and LK are chord

e) Secant - JL is the secant line

f) Tangent - JN is the tangent line

g) Central angle - ∠ LPM is the central angle.

h) Inscribed angle - ∠NLK is the inscribed angle

i) Minor arc - NK is the minor arc

j) Major arc - MLN is the minor arc

k) Semicircle - NKL and NML are the semicircles.