Answer:
No.
Step-by-step explanation:
It is not because 20 is not a perfect square.
Answer: 17
d =13 cm
r = 6.5 cm
The diameter is the distance across the circle, going through the center
d = 13 cm
The radius is 1/2 of the diameter
r = d/2 = 13/2 = 6.5 cm