Mathematics

Lara Blanchard

21 March, 18:26

Lisandro is using this diagram to find the equation of a circle. He notices that the radius, the blue line, and the red line form a right triangle. Which shows his correct reasoning and equation

a) The length of the red line is |x + h|.

The length of the blue line is |y + k|.

The equation of a circle is (x + h) 2 + (y + k) 2 = r2.

b) The length of the radius is r.

The area of a circle is πr2.

The equation of the circle is y = πr2x.

c) The length of the red line is |x - h|.

The length of the blue line is |y - k|.

The equation of a circle is (x - h) 2 + (y - k) 2 = r2.

d) The length of the red line is |x - h|.

The length of the blue line is |y - k|.

The equation of a circle is (x - h) 2 + (y - k) 2 = r.