Tolong dibantu ya,nmr 21&30 dan beserta caranya... TERIMA KASIH...
subebe
21. Luas juring 60 derajat = 60/360 x 22/7 x (7 + 14) (7+14) = 1/6 x 22/7 x 21 x 21 = 231 cm² Luas yang diasir = 231 - (60/360 x 22/7 x 7 x 7) = 231 - (1/6 x 22 x 7) = 231 - 25,67 = 205,33 (A) 30. Keliling juring 120 derajat = 120/360 x 2 x 22/7 x 21 = 1/3 x 2 x 22/7 x 21 = 44 Keliling asir = 44 + 21 + 21 = 86 (C)
= 1/6 x 22/7 x 21 x 21 = 231 cm²
Luas yang diasir = 231 - (60/360 x 22/7 x 7 x 7)
= 231 - (1/6 x 22 x 7)
= 231 - 25,67
= 205,33 (A)
30. Keliling juring 120 derajat = 120/360 x 2 x 22/7 x 21
= 1/3 x 2 x 22/7 x 21
= 44
Keliling asir = 44 + 21 + 21 = 86 (C)