tolong jawab pakai cara no. 1,4,&5

1. keliling segitiga sama sisi = 3 x s
                                          = 3 x 7,5 = 22,5cm
4. keliling 1/2 lingkaran + (2x20 + 7)
1/2 x pi x d + (2 x 20 +7)
1/2 x 22/7 x 7 + 47
11 + 47 = 58 cm

5. 15 + 7 + 8 + 9 + 12 = 51 cm