Question

In any triangle if a, b, c, are the lengths of three sides of a triangle. St s-a =7 s-b =5 s-c =3. Then perimeter of ∆ is _______.

Answer 1

perimeter of triangle=sum of its side

p=a+b+c and p=2s so s=p/2-------1,where s is semi perimeter...

as per question s-a+s-b+s-c=15

so 3s-(a+b+c)=15

3s-2s=15........from 1

s=15

p=2s=15×2=30.....your required answer thank you...