In each of the following, state if the statement is true (T) or false (F): A triangle has three sides. A triangle may have four vertices. Any three line-segments make up a triangle. The interior of a triangle includes its vertices. The triangular regain includes the vertices of the corresponding triangle. The vertices of a triangle are three collinear points. An equilateral triangle is isosceles also. Every right triangle is scalene. Each acute triangle is equilateral. No isosceles triangle is obtuse.