See question here.
Consider the triangles ACD and BCE.
In these triangles AC = BC because ABC is equilateral and CD = CE because CDE is equilateral.
Angle ACD = angle BCE because both are α plus 60°.
So ACD and BCE have two pairs of equal sides and an equal included angle, which means they are congruent and consequently AD = BE.
Not only are they equal, but they intersect at 60°. Can you give a proof?
Solution to Geometry Question 13 August
See question here.
Consider the triangles ACD and BCE.
In these triangles AC = BC because ABC is equilateral and CD = CE because CDE is equilateral.
Angle ACD = angle BCE because both are α plus 60°.
So ACD and BCE have two pairs of equal sides and an equal included angle, which means they are congruent and consequently AD = BE.
Not only are they equal, but they intersect at 60°. Can you give a proof?