Answer:
For 9:
For you to get to figure y you just divide all the triangle sides on X by 3 so: 9÷3=3, 9÷3=3, 12÷3=4 and the answers to those divisions are the sides on triangle Y.
To get from figure Y back to X again, you do the opposite and MULTIPLY your sides by 3: 3·3=9, 3·3=9, 3·4=12 SO THE ANSWER IS: 3
For 10:
To get to figure Y you add 6 to your sides and then to get from figure Y to X you SUBTRACT 6
THE ANSWER IS: 6
