The value of ∠ABC is 64 degree at x = 19 degree ,therefore Yin is not right about the value of x .
<h3>What is a Triangle ?</h3>
A triangle is a polygon with three sides , angles and vertices.
It is given that
m∠ABC = (4x – 12)°
m∠ACB = (2x + 26)°
Let m∠ACB = y degree
It is asked that if x =19 degree , is the triangle equilateral
m∠ABC = (4x – 12)° = 4 *19 -12 = 64 degree
As in an equilateral triangle , the angles are all equal and equal to 60 degree.
If the value of ∠ABC is 64 degree at x = 19 degree ,therefore Yin is not right about the value of x .
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