find the measures of the angles made by the intersecting lines at the vertices of an equilateral triangle
In an equilateral triangle , all angles are equal and sum of the angles in a triangle is 180°.
Let x be the equal angle of equilateral triangle.
In ΔABC,
∠A+∠B+∠C=180°
As, it is given that ,
∠A=∠B=∠C=x
⇒x+x+x = 180°
⇒3x = 180°
⇒x = 180°/3
⇒x=60°
Thus, the measure of each angle in an equilateral triangle = 60°