An ant is moving around a few food pieces of different shapes scattered on the floor. For which food piece would the ant have to take a longer round? Remember, the circumference of a circle can be obtained by using the expression c = 2πr, where r is the radius of the circle
Solution:
(a) Radius of the semicircle part = (2.8/2) cm = 1.4 cm
Perimeter of the circle = 2πr
Perimeter of the semicircle = πr
The perimeter of the food piece = 2.8 cm + πr
= 2.8 cm + (22/7 × 1.4) cm
= 2.8 cm + 4.4 cm
= 7.2 cm
(b) Radius of semicircle part = 2.8/2 = 1.4 cm
Perimeter of the food piece = 1.5 cm + 2.8 cm + 1.5 cm + πr
= 5.8 cm + (22/7 × 1.4) cm
= 5.8 cm + 4.4 cm
= 10.2 cm
(c) Radius of the food piece = 2.8/2 = 1.4 cm
Perimeter of the food piece = 2 cm + πr + 2 cm
= 4 cm + (22/7 × 1.4) cm
= 4 cm + 4.4 cm
= 8.4 cm
Thus, the ant will have to take a longer round for food piece in (b) because the perimeter of the figure given in (b) is the greatest among all
☛ Check: NCERT Solutions for Class 8 Maths Chapter 11
Video Solution:
An ant is moving around a few food pieces of different shapes scattered on the floor. For which food piece would the ant have to take a longer round? Remember, the circumference of a circle can be obtained by using the expression c = 2πr, where r is the radius of the circle
Class 8 Maths NCERT Solutions Chapter 11 Exercise 11.1 Question 5
Summary:
An ant is moving around a few food pieces of different shapes scattered on the floor. (a) The perimeter of the food piece is 7.2 cm (b) The perimeter of the food piece is 10.2 cm (c) The perimeter of the food piece is 8.4 cm. The ant will have to take a longer round for food piece in (b) because the perimeter of the figure given in (b) is the greatest among all
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