In triangle ABC it is known that AB = BC, angle ABC = 144 degrees. Find the angle of the BCA.

Find the angle of the triangle;

To do this, let’s analyze the condition of the task;

Since the two sides of the triangle are equal, it means that the triangle is isosceles;

And if the triangle is isosceles, then from the properties of this triangle, the angles at the base of the isosceles triangle are equal;

Let’s designate the unknown angle by the letter “X” and write down that;

BCA angle = BAC = X;

And since the sum of all the angles of the triangle is 180 °, then we can write down the equation;

ABC + 2X = 180 °;

Let’s substitute the data;

144 + 2X = 180;

2x = 180 – 144;

2X = 36;

X = 36/2;

X = 18 °;

Answer: BCA angle = 18 °.