What is the equation for half a circle?

Related questions

1. What is the radius of a circle calculator?
2. What is the vertex of a circle?
3. How do you find the Directrix?
4. How do you find the equation of a quarter of a circle?
5. What is the general equation of an ellipse?
6. How do you find the equation of the top half of a circle?
7. Who discovered the equation of a circle?
8. How do you find the radius of a circle?
9. What does the P stand for in the equation of a parabola?
10. What are the four types of conics?

Tags

1. #radius
2. #again
3. #semicircle
4. #circle
5. #perimeter
6. #divide
7. #circumference
8. #where
9. #however
10. #formula