(B). What impression do you form of Wanda Petronski on the basis of reading the lesson
‘The Hundred Dresses’? Why was there no reply of the letter written to Wanda by the
girls?
Answers
Answer:
Correct Question -
The circumference of two circle are in the ratio 2 : 3. Find the ratio of their areas.
Given -
Ratio of their circumference = 2:3
To find -
Ratio of their areas.
Formula used -
Circumference of circle
Area of circle.
Solution -
In the question, we are provided, with the ratios of the circumference of 2 circles, and we need to find the ratio of area of those circle, for that first we will use the formula of circumference of a circle, then we will use the formula of area of circles. We will be writing 1 equation in it too.
So -
Let the circumference of 2 circles be c1 and c2
According to question -
c1 : c2
Circumference of circle = 2πr
where -
π =
r = radius
On substituting the values -
c1 : c2 = 2 : 3
2πr1 : 2πr2 = 2 : 3
=
= [Equation 1]
Now -
Let the areas of both the circles be A1 and A2
Area of circle = πr²
So -
Area of both circles = πr1² : πr2²
On substituting the values -
A1 : A2 = πr1² : πr2²
=
=
= [From equation 1]
So -
=
The ratio of their areas is 4 : 9
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