Answer:
The length of the radius is <u><em>2.95 units </em></u>
Step-by-step explanation:
trapezium area
A=a+b/2(h)
Whole: A=8+10/2(6)
A=54 cm
Hole: 5+7/2(3)
a=18
54cm-18cm= 36
area of shaded region is 36cm.
64