The Letters R and θ Represent Polar Coordinates $$r = 5$$

Multiple Choice

The letters r and θ represent polar coordinates. Write the equation using rectangular coordinates (x, y) .
- $$r = 5$$

A) $x + y = 5$
B) $x ^ { 2 } - y ^ { 2 } = 25$
C) $x ^ { 2 } + y ^ { 2 } = 25$
D) $x + y = 25$