Samacheer Kalvi 8th Maths Solutions Term 1 Chapter 2 Measurements Ex 2.1
Samacheer Kalvi 8th Maths Solutions Term 1 Chapter 2 Measurements Ex 2.1
Tamilnadu Samacheer Kalvi 8th Maths Solutions Term 1 Chapter 2 Measurements Ex 2.1
Ex 2.1 Class 10 Samacheer Question 1.
Fill in the blanks:
(i) The ratio between the circumference and diameter of any circle is _________.
(ii) A line segment which joins any two points on a circle is a ______.
(iii) The longest chord of a circle is _______.
(iv) The radius of a circle of diameter 24 cm is ______.
(v) A part of circumference of a circle is called as _____.
Solution:
(i) π
(ii) chord
(iii) diameter
(iv) 12 cm
(v) an arc
8th Maths 2.1 Question 2.
Match the following
Solution:
(i) 3
(ii) 4
(iii) 5
(iv) 2
(v) 1
Class 8 Maths Exercise 2.1 Solution Question 3.
Find the central angle of the shaded sectors (each circle is divided into equal sectors)
Solution:
Exercise 2.1 Class 8 Question 4.
For the sectors with given measures, find the length of the arc, area and perimeter, (π = 3.14)
(i) central angle 45°, r = 16 cm
(ii) central angle 120°, d = 12.6 cm
(iii) central angle 60°, r = 36 cm
(iv) central angle 72°, d = 10 cm
Area of the sector missing
Perimeter of the sector
P = l + 2r units
P = 6.28 + 2(5) cm
P = 6.28 + 10 cm
P = 16.28 cm
Samacheer Kalvi 8th Maths Solutions Term 1 Measurement Question 5.
From the measures given below, find the area of the sectors.
Samacheer Kalvi 8th Maths Book Solutions Question 6.
Find the central angle of each of the sectors whose measures are given below (π = 22/7)
Solution:
(i) Radius of the sector = 21 cm
Area of the sector = 462 cm2
lr\2 = 462
l×21\2 = 462
∴ Central angle of the sector = 120°
(ii) Radius of the sector = 8.4 cm
Area of the sector = 18.48 cm2
(iii) Radius of the sector = 35 m
Length of the arc l = 44 m
Samacheerkalvi.Guru 8th Maths Question 7.
Answer the following questions:
(i) A circle of radius 120 m is divided into 8 equal sectors. Find the length of the arc of each of the sectors.
(ii) A circle of radius 70 cm is divided into 5 equal sectors. Find the area of each of the sectors.
Solution:
(i) Radius of the circle r = 120 m
Number of equal sectors = 8
(ii) Radius of the sector r = 70 cm
Number of equal sectors = 5
Solution:
Central angle of the quadrant = 90°
Radius of the circle = 2 feet
Area of the quadrant = 3.14 sq. feet (approximately)
Maths Class 8 Chapter 2 Exercise 2.1 Question 12.
Dhamu fixes a square tile of 30 cm on the floor. The tile has a sector design on it as shown in the figure. Find the area of the sector, (π = 3.14).
Solution:
Side of the square = 30 cm
∴ Radius of the sector design = 30 cm
Given design in the design of a circular quadrant.
Area of the quadrant = 1/4 πr2 sq. units
= 1/4 × 3.14 × 30 × 30 cm2
= 3.14 × 15 × 15 cm2
∴ Area of the sector design = 706.5 cm2 (approximately)
Class 8 Maths 2.1 Exercise Question 13.
A circle is formed with 8 equal granite stones as shown in the figure each of radius 56 cm and whose central angle is 45°. Find the area of each of the granite. (π = 22/7)
Solution:
Number of equal sectors ‘n’ = 8
Radius of the sector ‘r’ = 56 cm
Area of the each sector = 1/n πr2 sq. units
= 1/8×22/7 × 56 × 56 cm2 = 1232 cm2
Area of each sector = 1232 cm2 (approximately)
The Complete Educational Website