Tolong bantu kakJangan ngasal​

a. r = 10 cm

b. 136,89 cm²

c. 61,17°

Penjelasan dengan langkah-langkah:

a. 135/360 x 3,14 x r² = 117,75

3/8 x 3,14 x r² = 117,75

9,42/8 x r² = 117,75

r² = 117,75 : 9,42/8

= 117,75 x 8/9,42

= 100

r = √100 = 10 cm

b. L = 80/360 x 22/7 x 14 x 14

= 136,89 cm²

c. n/360 x 22/7 x 42 x 42 = 942

n x 5544 = 942 x 360

5544n = 339.120

n = 338.120 : 5544

= 61,17°