Answer:
r = 10/√3 ≈ 5.7735 cm
Explanation:
Each coloured region is the same area, and we have 3 areas.
So, the area of purple circle represents (1/3) of the total area.
∴The radius of purple circle is r, and the radius of outer circle is 10 cm.
The area of the purple circle = π r²
The total area = area of outer circle = π * 10²

So, the radius of the purple circle (r) = 5.7735 cm