Question

the average length of 3 side of a triangle is 19 cm ,What is its perimetre​

Answer 1

Step-by-step explanation:

$let \\ \: the \: sides \: are = a . b \: and \: c \\ according \: t o \: the \: question \\ \frac{a + b + c}{3 } = 19 \\ = > a + b + c = 19 \times 3 \\ = 57$

As we know that

${\boxed{perimeter=a+b+c}}$

Hence the perimeter is${\boxed{=57}}$