Answer:
If their angles are the same, if they are proportional, if it states so
Step-by-step explanation:
I don't see the image you sent, but just naming different things that proves how triangles are similar.
Step-by-step explanation
The orange machine, the very end of the shovel part. That line is a slope. The middle part of the scooper could also be a slope. The very beginng part of the scooper is also a slope. The bottom part of the scooper is also a slope. The bottom part at the end of the scooper could also be slope.
-2/3x+9=4/3x-3 original problem add 2/3x to both sides
9=6/3x-3 simplify 6/3 to 2 and add 3 to both sides
12=2x divide both sides by 2
x=6
hope that helps