PQ = 外公切線長
PQ^2 = (9 + 6)^2 - (9 - 6)^2 = 225 - 9 = 216
=> PQ = √216 = 6√6
∠AEB = 90度 (如需證明我再補充說明)
EA^2 + EB^2 = AB^2 = (9 + 6)^2 = 15^2 = 225
PQ = 外公切線長
PQ^2 = (9 + 6)^2 - (9 - 6)^2 = 225 - 9 = 216
=> PQ = √216 = 6√6
∠AEB = 90度 (如需證明我再補充說明)
EA^2 + EB^2 = AB^2 = (9 + 6)^2 = 15^2 = 225
謝謝