Question

If the sum of the circumferences of the two circles with radii \[r_1\] and  \[r_2\] is equal to the circumference of a circle of radius \[r\] then 

Options

• \[r = r_1 + r_2\]

• \[r_1 + r_2 > r\]

• \[r_1 + r_2 < r\]

• None of these 

Answer 1

The circumference of the circle with radius r = circumference of the circle with radius \[r_1\] + circumference of the circle with radius  \[r_2\] 

\[2\pi r = 2 \pi r_1 + 2 \pi r_2 \]
\[ \Rightarrow r = r_1 + r_2\]