1) Firstly, we'll need to find the length of all legs. We'll use the distance formula derived from the Pythagorean Theorem
Since an isosceles triangle has at least 2 congruent sides then this is an Isosceles Triangle.
2) The Perimeter (2P) is the sum of all sides' length of a polygon. Hence
3) So the answer is Isosceles Triangle and 2P =10+2√5