Answer:
X= 6
Step-by-step explanation:
We can see they are two right triangles that share a hypotenuse. They also have two sides that are the same (the radius of the circle). The hypotenuse that separates the triangles also cuts the angle ABC into two. Each of these half angles must be equal.
So we have an an Angle Angle Side right triangle congruency. Which means that the two triangles are proportional.
Another way to see it is that the two triangles have two angles that are equal so the third must be equal since all triangles have angles that add up to 180 degrees. Since all the angles are the same and they share a congruent side, then all sides must be the same.
The two radius legs are the same and congruent so the two other legs must be the same. So 4x - 9 = 15, and x = 6.
