No 3-5 please pakai cara ama jawaban

3.  L = 2phi x rx t = 2 x 22/7 x 7 x 15 = 44 x 15 = 660

4. V = 1/3 phi r² t = 1/3 x 3,14 x 8 x 8 x 15 =1004,8

5. L = 4 phi r² = phi d² = 22/7 x 21 x 21 = 22 x 21 x 3 = 1386