Please help me find the missing measurements of this :)

Answer:
4mm
Step-by-step explanation:
The ratio of the two congruent shapes are 2.5:1
15 : 6 = 2.5 : 1
15/6 = 2.5
5 : 2 = 2.5 : 1
5/2 = 2.5
Therefore, 10 : x = 2.5 : 1
10/x = 2.5
x = 4
Answer: 15, 2, 6, and 5
Step-by-step explanation: they are equal to the measurements listed