The angle ABC is 86°.
By geometry, we know that triangles are formed by knowing three distinct points in a plane. In this case, the three points (A, B, C) are on the circumference. In addition, we know that the sum of the internal angles within a triangle equals 180°.
Then, the size of the angle ABC is found by the following expression:
[tex]\angle ABC = 180^{\circ} - \angle BAC - \angle ACB[/tex] (1)
If we know that [tex]\angle BAC = 23^{\circ}[/tex] and [tex]\angle ACB = 71^{\circ}[/tex], then the value of the angle ABC is:
[tex]\angle ABC = 180^{\circ} - 23^{\circ} - 71^{\circ}[/tex]
[tex]\angle ABC = 86^{\circ}[/tex]
The angle ABC is 86°.
We kindly invite to see this question on angles: https://brainly.com/question/18060525
