Solution:

`"Here " a=3, b=4, c=5" (Given)"`
`"We know that,"`
`"Perimeter" = a + b + c`
` = 3 + 4 + 5`
` = 12`
` `
`"SemiPerimeter" = s = (a + b + c)/2`
` = 12/2`
` = 6`
`"Here " a=3, b=4, c=5" and semiPerimeter" = 6`
`"We know that,"`
`"Area" = sqrt(s (s  a) (s  b) (s  c))`
` = sqrt(6 (6  3) (6  4) (6  5))`
` = 6`


