Determine the radius of the penny

Answer:
9.5 mm
Step-by-step explanation:
The black line on the right of the penny represents the diameter: the measure from edge to edge of a circle.
We want to find the radius, the measure from the center to the edge of the circle. The radius is half of the diameter.
r=d/2
We know that the diameter is 19 millimetres. Substitute 19 in for d.
r=19/2
Divide
r=9.5
The radius is 9.5 millimetres
Answer:
Your answer would be B 9.5 mm
Step-by-step explanation:
The diameter is the full length of a circle and the radius is half. The diameter is 19 mm and 9.5 is half of 19 so 9.5 mm is the radius. I hope this helps. : )