no 8???mau nanya no 9 itu arsiran = persegi- 1/4 ling.??? dan no 10 apakh tinggi juga dikurangi ketebalan...mohon penjelasannya kawand....

8][

a = √42,9
a² = 42,9

s = √(0,95) = √(95/100) = 1/10 √95
√95 = 10s

42,9 + √95 = a² + 10s

9][
r = 10,5 cm = 21/2

Luas yg diarsir
= r² - 1/4 πr²
= (21/2)² - 1/4 . 22/7 . (21/2)²
= (21/2)² [ 1 - 11/14)
= (21/2)² . 3/14
= 21/2 . 9/4
= 189/8 cm²
= 23,625 cm²