Question

geometric definitions
three students attempt to define what a circle is.
can you match the teachers comments to the definitions?
definition of a circle|teachers comments
ivys definition: a 2d geometric shape that is both round and closed, having no corners.|your definition is close, but it isnt precise enough. a half - circle, for example, would also fit your definition.
ethans definition: given a distance r (call it the radius), a circle is the set of all points r units away from some fixed point c (call it the center) in a plane.|sorry, this is incorrect. an ellipse, for example, would also fit your definition.
ebukas definition: a 2 - dimensional shape made by drawing a curve that is always the same distance from a center.|correct! your definition is very clear and precise.

Explanation:

Ivy's definition is too general as semi - circles also fit it. Ethan's definition is incorrect as ellipses also satisfy the condition of points at a certain distance from a fixed point in a plane. Ebuka's definition correctly and precisely describes a circle as a 2 - D shape with a curve equidistant from a center.

Answer:

Ivy's definition - Your definition is close, but it isn't precise enough. A half - circle, for example, would also fit your definition.
Ethan's definition - Sorry, this is incorrect. An ellipse, for example, would also fit your definition.
Ebuka's definition - Correct! Your definition is very clear and precise.