If the area of the circular pathway is 352 sq. cm and the outer radius

1.	If the area of the circular pathway is 352 sq. cm and the outer radius is 16 cm, find the inner radius.
Answer» Given outer radius R = 16 cm Area of the circular pathway = πR² = πr² Area of the circular pathway = 352 sq. cm πR² – πr² = 352 cm² π(R² – r²) = 352 16² – r² = \(\frac{352\times7}{22}\) 16² – r² = 16 x 7 16² – r² = 112 16² – 112 = r² r² = (256 – 112) cm² r² = 144 cm² r = 12 cm Inner radius r = 12 cm

If the area of the circular pathway is 352 sq. cm and the outer radius is 16 cm, find the inner radius.

Answer»

Given outer radius R = 16 cm

Area of the circular pathway = πR² = πr²

Area of the circular pathway = 352 sq. cm

πR² – πr² = 352 cm²

π(R² – r²) = 352

16² – r² = \(\frac{352\times7}{22}\)

16² – r² = 16 x 7

16² – r² = 112

16² – 112 = r²

r² = (256 – 112) cm²

r² = 144 cm²

r = 12 cm

Inner radius r = 12 cm