Identify the true statement. Explain why the statement is true. All isosceles triangles are obtuse triangles. If the base angles each measure less than \( 45^{\circ} \), the vertex angle will measure more than \( 90^{\circ} \). All isosceles triangles are right triangles. The vertensingle in an isosceles triangle can measure \( 90^{\circ} \). All equilateral triangles are obtuse triangles. All angles in an equilateral triangle measure \( 120^{\circ} \). All equilateral triangles are acute triangles. All angles in an equilateral triangle measure \( 60^{\circ} \).

The true statement is: "All equilateral triangles are acute triangles. All angles in an equilateral triangle measure \( 60^{\circ} \)." This statement is true because, by definition, an equilateral triangle has three equal sides and, consequently, three equal angles. Each angle measures \( 60^{\circ} \), which is less than \( 90^{\circ} \), making all equilateral triangles acute. Isosceles triangles can actually take on different forms, including acute, right, and obtuse types. For instance, an isosceles triangle can have its base angles measure \( 50^{\circ} \) and \( 50^{\circ} \) making the vertex angle \( 80^{\circ} \), hence it being acute. Since there's flexibility in the angles of isosceles triangles, they aren't restricted to being just one type of triangle.