Suppose we need the formula for the area of a circle for some computation. Like many people who learned geometry too long ago to recall with any certainty, two expressions may pop into our mind when we think of circles: πr^2 and 2πr . One expression is the circumference of a circle of radius r and the other is its area. But which is which?
Je me demande comment dire en français But which is which ou comment rendre en français une idée voisine.