Answer:
exactly two sides are the same length
Step-by-step explanation:
Both AB and AC are diagonals of a rectangle that is 1 unit by 5 units. Hence they are the same length. BC is the diagonal of a square 4 units on a side, so will be a different length. A triangle with two (not three) sides the same length is an isosceles triangle, by definition.
∆ABC is an isosceles triangle
___
The lengths are found using the Pythagorean theorem:
same lengths: √(1² +5²) = √26
third side: √(4² +4²) = √32 ≠ √26
