Question

what is the radius of this circle?

Explanation:

Step1: Observe the circle on grid.

The circle seems to have a diameter that spans 2 grid - units.

Step2: Recall radius - diameter relation.

The radius $r$ of a circle is half of its diameter $d$, i.e., $r=\frac{d}{2}$.

Step3: Calculate the radius.

Since $d = 2$, then $r=\frac{2}{2}=1$.

Answer:

1