Question

david had a tile that was an equilateral triangle. each angle of the triangle measured 60°. which statements best justifies davids conclusion? all acute angles have a measure of 60°. every equilateral triangle is also an isosceles triangle. the sum of the measures of the angles in a triangle is 180° and the three angles are congruent. the measure of an exterior angle of a triangle is the sum of the measures of its two remote interior angles.

Explanation:

An equilateral triangle has all angles congruent. The sum of interior - angles of a triangle is 180°. So, if all three angles are equal, each angle is $\frac{180^{\circ}}{3}=60^{\circ}$.

Answer:

The sum of the measures of the angles in a triangle is 180° and the three angles are congruent.