Question 755350
A right angled triangle with height = 3 units
and a base = 12 units.
We find the hypotenuse, which is the third side
facing the 90 degree right angle.
Hypotenuse^2 = 3^2 + 12^2
 Hypotenuse^2 = 153
    Hypotenuse = square root of 153
    Hypotenuse = 12.4 units
The perimeter = 2( 12.4) + 12 units
            = 36.8 units.
Hope this helps.
:-)