Karnataka Board Class 9 Maths Chapter 12 Circles Ex 12.1
Question 1.
Fill in the blanks : (Answers are filled)
(i) The centre of a circle lies in the interior of the circle, (exterior/interior)
(ii) A point, whose distance from the centre of a circle is greater than its radius lies in the exterior of the circle, (exterior/interior)
(iii) The longest chord of a circle is a diameter of the circle.
(iv) An arc is a semicircle when its ends are the ends of a diameter.
(v) Segment of a circle is the region between an arc and chord of the circle.
(vi) A circle divides the plane, on which it lies, in three parts.
2. Write True or False: Give reasons for your answers.
Question 1.
Line segment joining the centre to any point on the circle is a radius of the circle.
Answer:
True. Each point in the circumference are equidistant from the centre of the circle. That distance is called radius of the circle.
Question 2.
A circle has only finite number of equal chords.
Answer:
False. A circle has infinite number of equal chords because in a circle there are infinite points.
Question 3.
If a circle is divided into three equal arcs, each is a major arc.
Answer:
False. If equilateral triangle is constructed in interior of the circle, the three equal parts are called minor arcs.
Question 4.
A chord of a circle, which is twice as long as its radius, is a diameter of the circle.
Answer:
True. Diameter is a line segment which passes through centre of the circle.
Question 5.
Sector is the region between the chord and its corresponding arc.
Answer:
False. The part which joins centre of the circle to the end points of arc, area coveted with two radii and arc s is called sector.
Question 6.
A circle is a plane figure.
Answer:
True. A circle has two dimension.