Please help!! thanks

Answer:
8
Step-by-step explanation:
do you see how left side equals 10 and the right side equals 10 as well (6+4=10)
the bottom side equals 13
one of the top sides equal 5
so 13-5=8
Answer:
8cm
Step-by-step explanation:
? = 13cm - 5cm = 8cm.
if you add 5 to 8 it will equal 13.