An acute triangle (or acute-angled triangle) is a triangle with three acute angles (less than 90°). An obtuse triangle (or obtuse-angled triangle) is a triangle with one obtuse angle (greater than 90°) and two acute angles.

How can a triangle have 3 acute angles?

A triangle where all three internal angles are acute (less than 90 degrees). … In any triangle, two of the interior angles are always acute (less than 90 degrees)*, so there are three possibilities for the third angle: Less than 90° – all three angles are acute and so the triangle is acute.

Does an isosceles triangle have 3 acute angles?

Isosceles triangles always have two equivalent interior angles, and all three interior angles of any triangle always have a sum of degrees. Since this is an obtuse isosceles triangle, the two missing angles must be acute angles.