Answer:
7.7cm to 1 decimal place
Explanation:
for 1st circle, area of full circle = π r² = π (12)² = 144π
area of sector for 1st circle = (42/360) X 144π = 16.8π
for sector of 2nd circle, area = 16.8π
area of sector = (103/360) π r² = 16.8π
π r² = (16.8π) ÷ (103/360)
= 184.469.....
r² = 58.718.....
r = 7.7 cm to 1 decimal place