Answer:
Step-by-step explanation:
1. area of square=10²=100 cm²
area of circle=πr²=π×2.5²=6.25π cm²
reqd. area=100-6.25π ≈80.375 cm²
2.
area of circle=π×2.5²=6.25π≈6.25×3.14≈19.625 cm²
area of rectangle=4×3=12 cm²
reqd. area=19.625-12≈7.625 cm²
3.
area of two circles=2×π×3²=18π≈18×3.14≈56.52 cm²
area of square=12²=144 cm²
reqd. area=144-56.52≈87.48 cm²
4.
area of smaller circle=π×4²=16π cm²
area of bigger circle=π×8²=64π cm²
area of two circles=16π+64π=80π cm²
diameter of bigger circle=4+4+8+8=24 cm
diameter of biggest circle=π×12²=144π
area of shaded region=144π-80π=64π≈200.96 cm²