Question

what is the radius of this circle?

Explanation:

Step1: Identify the grid size

Each grid square has a side length of 1 unit (since the x and y axes are labeled with integers at intervals of 2, but the grid lines are at each integer, so each square is 1x1).

Step2: Observe the circle's radius

The circle is centered at (0, -9) (from the grid, the center is at the intersection of x=0 and y=-9). The circle extends from the center to the edge, and visually, it spans 1 unit (from the center to the edge, which is 1 grid square). Wait, actually, looking at the circle, the diameter seems to be 2 units? Wait no, the circle is drawn with a radius of 1 unit? Wait, no, let's check the grid. The center is at (0, -9), and the circle goes from, say, x=-1 to x=1 (so width 2) and y=-10 to y=-8 (height 2)? Wait, no, the circle is small. Wait, the grid lines: each major tick is 2 units? No, the x-axis has -10, -8, -6,... 8, 10, so each grid line is 1 unit (since between -10 and -8 there are two grid lines? Wait no, the distance between -10 and -8 is 2 units, with one grid line in between? Wait, no, the graph has a grid where each square is 1 unit. Wait, the center is at (0, -9), and the circle has a radius of 1 unit, because from the center (0, -9) to the edge, it's 1 unit (e.g., from y=-9 to y=-8 is 1 unit, and x from 0 to 1 is 1 unit). Wait, actually, looking at the circle, it's a small circle with radius 1 unit? Wait, no, maybe I misread. Wait, the circle is drawn with a radius of 1 grid square, so the radius is 1? Wait, no, let's count the grid squares. The center is at (0, -9). The circle's edge is at x=1, x=-1, y=-8, y=-10? No, the circle is between x=-1 and x=1 (so diameter 2, radius 1) and y=-10 and y=-8 (diameter 2, radius 1). So the radius is 1 unit? Wait, no, maybe the grid is such that each square is 1 unit, so the radius is 1. Wait, but maybe I made a mistake. Wait, the problem is to find the radius. Looking at the circle, it's a small circle with radius 1. Wait, no, let's check again. The center is at (0, -9). The circle extends 1 unit in all directions (left, right, up, down), so the radius is 1.

Answer:

1