Common Core · High school
HSG-GPE.A.1
High school — Derive the equation of a circle of given centre and radius using the Pythagorean theorem; complete the square to find the centre and radius of a circle given by an equation.
The skill that covers it
What a student should be able to do
- Write the equation of a circle from its centre and radius, or from its centre and a point on it.
- Read the centre and radius from (x - h)2 + (y - k)2 = r2.
- Complete the square to rewrite x2 + y2 + ax + by + c = 0 in centre-radius form.
- Decide whether a point lies on, inside or outside a circle.