Circles

Vocabulary Words

Radius (r): Distance from center of the circle to the edge (halfway across)

Diameter (d): Distance through the center of the circle from edge to edge (all the way across).

Circumference (c): Distance around the outside of the circle.

Formulas:

r = d ÷ 2

d = r × 2

c = π × d

A = π × r ²