NCTB Class 8 Math Chapter Ten Exercise 10.3 Solutions by Math Expert. Bangladesh Board Class 8 Math Solution Chapter Ten Circle 10.3 Solution.
1> On a plane
(i) Innumerable circles can be drawn with two particular points.
(ii) the three points are not on one straight line. Hence, only one circle can be drawn.
(iii) A straight line can intersect at more than two points in a circle. Which one of the following is correct.
2> In a circle with radius 2r-
(i)’Circumference is 4 π r unit.
(ii) Diameter is 4r unit.
(iii) Area is 2 π2r2 sq. unit.
Which one of the following is correct?
3> For a circle with radius 3 cm, What will be the length of the chord 6 cm from the centre in cm?
4> What will be the area of a circle with unit radius?
5> What will be the length of a radius of a circle with circumference 23 cm?
6> What will be the area in between the space of the two uni centered circles with radius 3 cm and 2 cm?
7> The diametre of a wheel of a vehicle is 38 cm. What will be the distance covered by two complete round?
Answer questions 8, 9 and 10 on the basis of the following figure:
8> In the figure, 0 is the centre of the circle? what will be the lengths of CD in cm?
9> AB=CD, OB =3 cm. What will be the radius of the circle in cm?
10> If AB>CD, which of the following will be correct?
12> Find the circumference of the circles with the following radius:
13> Find the area of the circles given below :
14> If the circumference of a circular sheet is 154 cm, find its radius. Also, find the area of the sheet.
15> A gardener wants to fence a circular garden of diameter 21m. Find the length of the rope he needs to purchase if he makes 2 rounds of the fence. Also, find the cost of the rope if it costs Tk. 18 per metre. 14mm
Ans: Circumference = 2 πr
= 2 x 22/7 x 21
Rope needs= (132 x 2)
Therefore, 1m. rope cost 18 tk
264m. rope cost wil be (18 x 264) = 4752 tk.
16> Find the perimeter of the given shape.
18> The height of a right circular cylinder of radius 5.5 cm is 8 cm. Find the area of the whole surfaces of the cylinder (T = 3.14)