D
1) Examining the sides of that triangle, we can state that this is an equilateral triangle (at least 2 sides have the same measure). But Since isosceles is a triangle that has 2 sides with the same measure.
Then we can state that about their sides this is an equilateral and isosceles triangle.
2) Examining their angles. An equilateral triangle has 3 angles with 60º measure. A 60º angle is lesser than 90º, then we can classify this triangle as an acute triangle
3) Hence, the answer is D
