Q. 2. Find the area of the following circles, given that:
(a) radius = 14 mm
(b) diameter = 49 m
(c) radius = 5 cm
( Take π = 22/7 )
Answers
Step-by-step explanation:
a) Radius = 14 mm
r = 14 mm
Therefore,
Area of the circle
= πr²
= 22/7 (14)² = 22/7 × 14 × 14
= 616 mm²
b) Diameter = 49 m
Radius (r) = 49/2 m
Therefore,
Area of the circle
= πr² = 22/7 (49/2)² m²
= 22/7 × 49/2 × 49/2 m²
= 3773/2 m² = 1886.5 m²
c) Radius = 5 cm
r = 5 cm
Therefore,
Area of the circle
= πr² = 22/7 (5)² = 22/7 × 5 × 5
= 550/7 cm².
hope it helps you.
Step-by-step explanation:
Given :-
(a) radius = 14 mm
(b) diameter = 49 m
(c) radius = 5 cm
To find :-
Find the areas of the following circles ?
Solution :-
(a)
Given that
Radius of the circle (r) = 14 mm
We know that
Area of a circle whose radius is r units
= πr² sq units
Area of the given circle
=> A = (22/7)×14² sq.mm
=> A = (22/7)×14×14
=> A = (22×14×14)/7
=> A = 22×14×2
=> A = 616 sq.mm.
Area of the given circle is 616 sq.mm.
(b)
Given that
Diameter of the circle (d) = 49 m
Radius = Diameter/2
=> Radius of the circle = 49/2 m
We know that
Area of a circle whose radius is r units
= πr² sq units
Area of the given circle
=> A = (22/7)×(49/2)² sq.m
=> A = (22/7)×(49/2)×(49/2)
=> A = (22×49×49)/(2×2×7)
=> A = 11×49×7/2
=> A = 3773/2 sq.m
=> A = 1886.5 sq.m
Area of the given circle is 1886.5 sq.m
(or)
Given that
Diameter of the circle (d) = 49 m
Area of the circle whose diameter is d units = πd²/4 sq.units
Area of the given circle
=> A = (22/7)×(49)²/4 sq.m
=> A = (22×49×49)/(7×4)
=> A = (11×49×7)/2
=> A = 3773/2 sq.m
=> A = 1886.5 sq.m
Area of the given circle is 1886.5 sq.m.
(c)
Given that
Radius of the circle (r) = 5 cm
We know that
Area of a circle whose radius is r units
= πr² sq units
Area of the given circle
=> A = (22/7)×5² sq.cm
=> A = (22/7)×5×5
=> A = (22×5×5)/7
=> A =550/7
=> A = 78.57 sq.cm
Area of the given circle is 550/7 sq.cm or 78.57 sq.cm
Used formulae:-
→ Area of the given circle = πr² sq.units
→ Area of the given circle = πd²/4 sq.units
- r = radius
- d = diameter
- π = 22/7