Question

如圖，三角板中，，，．三角板繞直角頂點(diǎn)逆時(shí)針旋轉(zhuǎn)，當(dāng)點(diǎn)的對(duì)應(yīng)點(diǎn)落在邊的起始位置上時(shí)即停止轉(zhuǎn)動(dòng)，則點(diǎn)轉(zhuǎn)過的路徑長(zhǎng)為__________.

Answer 1

2.

試題分析：點(diǎn)B轉(zhuǎn)過的路徑長(zhǎng)是以點(diǎn)C為圓心，BC為半徑，旋轉(zhuǎn)角度是60度，根據(jù)弧長(zhǎng)公式可得．
∵AC=A′C，且∠A=60°
∴△ACA′是等邊三角形．
∴∠ACA′=60°
∴點(diǎn)B轉(zhuǎn)過的路徑長(zhǎng)是：．