Yin is incorrect because when the value of x is 19 both the angles is equal to \(64^\circ\) but in equilateral triangle all the angles must be equal to \(60^\circ\) and this can be determine by using the properties of equilateral triangle.
Given :
In triangle ABC, \(\angle\)ABC = (4x – 12)° and \(\angle\)ACB = (2x + 26)°.
In equilateral triangle all the three sides of the triangle are equal and all the interior angles are congruent to each other and equal to \(60^\circ\).
So, to prove that the given triangle ABC is an equilateral triangle than both the given angles must be equal to \(60^\circ\).
\(=4\times19-12\)
= 76 - 12
= \(64^\circ\)
\(= 2\times 19 + 26\)
= 38 + 26
= \(64^\circ\)
Therefore, Yin is incorrect because when the value of x is 19 both the angles is equal to \(64^\circ\) but in equilateral triangle all the angles must be equal to \(60^\circ\).
For more information, refer the link given below:
https://brainly.com/question/6238271
