問題: 平面幾何 (平行四邊形+相似三角形)
Consider △CPB and △BPM, ∠CPM = ∠BPM = 90º (given) ∠PMB = 180º - ∠BPM - ∠PBM = 90º - ∠PBM ∠PBC = ∠MBC - ∠PMB = 90º - ∠PBM ∴, ∠PMB = ∠PBC Therefore, △CPB ∼ △BPM (A.A.A. ∼). Now, consider △CPD and △BPN, ∠DCP = ∠DCB - ∠P...
Consider △CPB and △BPM, ∠CPM = ∠BPM = 90º (given) ∠PMB = 180º - ∠BPM - ∠PBM = 90º - ∠PBM ∠PBC = ∠MBC - ∠PMB = 90º - ∠PBM ∴, ∠PMB = ∠PBC Therefore, △CPB ∼ △BPM (A.A.A. ∼). Now, consider △CPD and △BPN, ∠DCP = ∠DCB - ∠P...
今日喺Facebook見到有人問咗一條看似簡單, 但係又唔可以就咁用計數機㩒個答案出嚟嘅數。想喺依度同大家分享一吓:(begin{align}&dfrac{84^{90}-64^{80}}{20^{70}} \&= dfrac{84^{90}}{20^{70}}-dfrac{64^{80}}{20^{70}} \&= (dfrac{84^{9}}{20^{7}})^{10}-(dfrac{64^{8}}{20^{7}})^{10} \&= (162668553.5...
大家一定有聽過"學如逆水行舟 不進則退"這句說話。但原來,亦有一些 初中數學問題 係同逆水行舟有關。其實只要明白當中道理, 這類數一D都唔難...... 我地先嚟睇一睇題目.... 喺做依條題目之前,我地先嚟諗一諗。假設隻船嘅引擎喺無開到,咁隻船喺河流入面會否移動呢? 答案當然係"會"! 咁係因為隻船會隨波逐流.... 隨波逐流?? 無錯! 咁即係話隻船會以 2 m/s嘅速度向河流下流移動。 明白依點後,假設船開返個引擎,而船嘅引擎可以比到一個 2 m/s 嘅...