Given: y = x - 6 (1) for the line x² + y² = r² (2) for the circle
When the line intercepts the circle, the x and y values will be equal. Equate the values of y by substituting (1) into (2). x² + (x - 6)² = r² x² + x² - 12x + 36 = r² 2x² - 12x + 36 = r²
