Explanation:
area of circle = πr²
internal radii - 3 cm = r1
external radii - 10 cm = r2
internal + external radii = πr1² + πr2²
= 22/7×3² + 22/7×10²
= 28.28 + 314.28
= 342.56 cm²
9.4m questions
12.2m answers