Question

what is the radius of this circle?

Explanation:

Step1: Observe the circle on graph

The circle seems to have a diameter of 2 units (by counting the grid - squares).

Step2: Use radius - diameter relationship

The radius $r$ of a circle is related to the diameter $d$ by the formula $r=\frac{d}{2}$. Since $d = 2$, then $r=\frac{2}{2}=1$.

Answer:

1