Question 757459
Not shown here, but refer to the picture that YOU described:


You want the sum of the lengths of the three sides.  The distance from where the two equal sides meet and the middle of the other side is not necessary, because you already have the three lengths of the triangle's sides.  


The perimeter of this triangle is 5+5+6=16 inches.  


That altitude or height description you gave would be useful for finding area.  Since this height is not given, and since you know it meets the 6" side making right angles, you could use pythagorean theorem to find this height size.