If a triangle has exactly one angle that is 60 degrees, how is the triangle classified?

A triangle with exactly one angle measuring 60 degrees can be classified as a scalene triangle. In a scalene triangle, all three sides are of different lengths, which typically also means that all three angles are of different measures. Since one angle is 60 degrees, the other two angles would also have to be different from each other and different from 60 degrees to ensure that the triangle is scalene and that the total measures of angles add up to 180 degrees.

An equilateral triangle, by contrast, has all three angles measuring 60 degrees, which does not fit the condition that specifies only one angle as being 60 degrees. An isosceles triangle has at least two angles that are equal, which also wouldn’t match the scenario presented here, where only one angle is known. Lastly, a right-angled triangle must contain one angle measuring exactly 90 degrees, which again contradicts the condition of having a triangle with only a single 60-degree angle.

Therefore, the only classification that fits the given condition is scalene, characterized by having all sides and angles unequal.