Answer: The answer is 13, read on to find out
Step-by-step explanation: The traingles are simliar so the values are similar as well. Find a lowest common factor of the values.
The lowest common factor is 4 because all the numbers can be divided by the number 4.
20 divided by 4 is 5 which is already shown on the graph
48 divided by 4 is 12
All we have to do now is 52 divided by 4
13
Hope I helped you answer the question! Have a great day/afternoon!