Question

Give reasons for why the answer is 60°.​

Answer 1

Answer:

Let the triangle name be ABC.

• Since, all the sides of the given triangle are equal. Therefore, triangle ABC is equilateral.
• In equilateral triangle, all angles are also equal. Therefore, angles between two sides of equilateral triangle is 60°,i.e., ∠BAC = ∠ABC = ∠BCA = 60°.
• Alternate interior angles are angles formed when two parallel or non-parallel lines are intersected by a transversal. The angles are positioned at the inner corners of the intersections and lie on opposite sides of the transversal.
• Here, the line BC and the line AD are parallel lines and the line AC is the transversal.

• Therefore, according to alternate interior angles definition, ∠BCA = ∠DAC = 60°.

I hope you understood it.