Question

the ratio of the raddi of two circle is5:9 find the ratio of their circumferences
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Answer 1

Answer:

the ratio of the diameters of two circles is 5:9, what is the ratio of their areas?

Solution:

Area of a circle = π⋅r2

To solve this problem let”s solve a problem:

We’ll increase the diameter by 2 on both circles to 10 and 18 which gives us a radius of 5 and 9.

And we solve:

Area of a circle(1) = π⋅52 , ==> 25 π

Area of a circle(2) = π⋅92 , ==> 81 π

The ratio of a circle with a diameter of 5 and 9.

Will have a area equal to the square of it’s diameter or 25 : 81

Answer is 25 : 81

hope it help you...