Respuesta :
Answer:
10 cm
Step-by-step explanation:
The perimeter of a equilateral triangle is
P = 3s where s is the side length
30 = 3s
Divide each side by 3
30/3 = 3s/3
10 = s
10cm. perimeter is simply adding up all the sides. so 10+10+10 is 30 giving you each side of a 3 sided figure