This can be proven by using congruent triangles. Because ACX=YCB are two adjacent angles, one angle is <ACB and the other being an angle that forms an equilateral triangle (which is 60 degrees), it means that ACX=<YCB=<ACB+60.

Now we can see that AC=YC, and CX=CB, these are both sets of sides for an equilateral triangle.

This means that triangles ACX and YCB are congruent triangles, this is because they both have two sides that are the same length, which means they are also the same angle. WE can determine that AX=BY because they are corresponding sides. The same argument can be applied to show that AX=CZ.

This proof will work for all triangles, but needs one small clarification when angle ACB>120 degrees. When the angle ACB=120 degrees, the angles ACX and YCB become 180 degrees each, the triangles ACX and YCB become trivial, this means that they will collapse and become straight lines of equal length. Given this the proof will still work.

When the angle ACB>120 degrees, both triangle ACX and YCB will sit completely outside the triangle ABC. Given this the proof should still hold because ACX=<YCB=(<ACB+60), but now we are working with the outside angles instead.

What i have:
This means that triangles ACX and YCB are congruent triangles, this is because they both have two sides that are the same length, which means they are also the same angle. WE can determine that AX=BY because they are corresponding sides. The same argument can be applied to show that AX=CZ.

This proof will work for all triangles, but needs one small clarification when angle ACB>120 degrees. When the angle ACB=120 degrees, the angles ACX and YCB become 180 degrees each, the triangles ACX and YCB become trivial, this means that they will collapse and become straight lines of equal length. Given this the proof will still work.

When the angle ACB>120 degrees, both triangle ACX and YCB will sit completely outside the triangle ABC. Given this the proof should still hold because ACX=<YCB=(<ACB+60), but now we are working with the outside angles instead.

What i need: i do not understand how to draw this

To draw the given triangle and understand the proof, follow these steps:

1. Start by drawing a triangle ABC with three sides AC, BC, and AB.

2. Identify the triangle's angles. In the proof, it is mentioned that angle ACB is the largest angle and angle ACX and angle YCB are adjacent to it. Note that angle ACB is greater than or equal to 120 degrees.

3. Now, draw a line segment AX starting from point A and extending towards the interior of the triangle. Similarly, draw a line segment BY starting from point B and extending towards the interior of the triangle.

4. To form an equilateral triangle, mark points C' and C'' on the line segments AX and BY, respectively, such that AX = CC' and BY = CC''. These points will help you establish congruent triangles.

5. Draw line segments AC' and BC''. These line segments will form two smaller triangles, ACX and YCB, respectively.

Now, you have successfully drawn the given triangle and the necessary line segments to understand the proof. The next step is to follow the reasoning provided in the proof to establish congruency between triangles ACX and YCB.

Keep in mind that if the angle ACB is exactly 120 degrees, the triangles ACX and YCB will become trivial, collapsing into straight lines of equal length. If the angle ACB is greater than 120 degrees, the triangles ACX and YCB will sit outside the triangle ABC. In this case, the proof applies to the corresponding outside angles.

By drawing the diagram, you can visualize the relationships between the angles and sides of the triangles, confirming the congruency of triangles ACX and YCB.