枚举归纳法是几何证明中常用的一种严格的推证方法。它要求就题设事项所有情况一一加以证明 ,才能得出一般的结论。例 1.·○ O1 和·○ O2 相交于点 B和 C,A是·○ O1上另一点 ,AT是·○ O1 的切线 ,又直线 AB和 AC分别交·○ O2 于点 D和 E,求证 :AT∥ DE。大多数学生的证明 Enumeration induction is a strict method of proof used in geometrical proof. It requires that all the circumstances of the subject matter be proven one by one to arrive at a general conclusion. Example 1. o O1 and o O2 intersect at points B and C, A is o O1, another point, AT is the tangent of o O1, and lines AB and AC intersect o O2 at points D and E, Verification: AT∥ DE. Proof of most students