滬教版四年級(jí)上冊(cè)數(shù)學(xué)-54-幾何小實(shí)踐(角的度量)課件

滬教版四年級(jí)上冊(cè)數(shù)學(xué)-54-幾何小實(shí)踐(角的度量)課件1212猜一猜，∠1和∠2誰(shuí)大？12∠2﹥∠1猜一猜，∠1和∠2誰(shuí)大？12∠2﹥∠121221212∠2比∠1大多少度？★∠2和∠1分別包含了多少個(gè)1°角12∠2比∠1大多少度？★∠2和∠1分別包含了多少個(gè)1°21∠2比∠1大多少度？10°10°10°10°10°10°10°∠2比∠1大10度！0°10°20°30°0°10°20°30°40°∠1=30°∠2=40°21∠2比∠1大多少度？10°10°10°10°10°101313310°10°10°10°10°10°10°10°10°10°10°10°10°10°10°10°∠3=160°0°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°310°10°10°10°10°10°10°10°10°10310°10°10°10°10°10°10°10°10°10°10°10°10°10°10°10°0°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°10°10°170°180°310°10°10°10°10°10°10°10°10°100°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°0°10°20°30°40°50°60°70°80°90°1120°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°∠1=30°我知道了！∠2是140°！10°10°10°10°0°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°10°0°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°∠2=40°30°120°10°20°30°40°50°60°70°80°900°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°10°0°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°210°10°20°30°40°50°60°70°80°90°1AOB∠AOB=60°0°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°10°0°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°AOB∠AOB=60°0°10°20°30°40°50°600°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°10°0°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°COD0°10°20°30°40°50°60°70°80°90°1COD∠COD=65°COD∠COD=65°量角器中心零刻度線(xiàn)零刻度線(xiàn)量角器中心零刻度線(xiàn)零刻度線(xiàn)合作學(xué)習(xí)1、完成練習(xí)一，組內(nèi)交流測(cè)量的方法和結(jié)果合作學(xué)習(xí)1、完成練習(xí)一，組內(nèi)交流測(cè)量的方法和結(jié)果AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB50你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB50判斷1∠1=20°∠1=15°判斷1∠1=20°∠1=15°判斷BOC∠BOC=145°判斷BOC∠BOC=145°判斷5∠5=135°∠5=125°判斷5∠5=135°∠5=125°這個(gè)角磨損了，聰明的你有辦法知道它原來(lái)的角度嗎？原來(lái)是50°這個(gè)角磨損了，聰明的你有辦法知道它原來(lái)的角度嗎？原來(lái)是50猜一猜，下面的角可能是多少度？猜一猜，下面的角可能是多少度？猜一猜，下面的角可能是多少度？猜一猜，下面的角可能是多少度？合作學(xué)習(xí)1、嘗試完成練習(xí)二，如果遇到困難，可請(qǐng)教學(xué)習(xí)同伴或老師？2、完成后在組內(nèi)交流，你測(cè)量的結(jié)果是多少？你是怎么測(cè)量的？你們的測(cè)量方法有哪些相同點(diǎn)和不同點(diǎn)？合作學(xué)習(xí)1、嘗試完成練習(xí)二，如果遇到困難，可請(qǐng)教學(xué)83°比一比，誰(shuí)能估得又對(duì)又快？83°比一比，誰(shuí)能估得又對(duì)又快？68°比一比，誰(shuí)能估得又對(duì)又快？68°比一比，誰(shuí)能估得又對(duì)又快？146°比一比，誰(shuí)能估得又對(duì)又快？146°比一比，誰(shuí)能估得又對(duì)又快？

放風(fēng)箏比賽時(shí)，規(guī)定用30米長(zhǎng)的線(xiàn)。比哪個(gè)風(fēng)箏放得高？該怎么辦呢？

只要把每根風(fēng)箏線(xiàn)的一端固定在地面上，分別量出它們與地面所形成的角的度數(shù)。你知道嗎？放風(fēng)箏比賽時(shí)，規(guī)定用30米長(zhǎng)的線(xiàn)。比哪個(gè)風(fēng)箏放得高？該怎滬教版四年級(jí)上冊(cè)數(shù)學(xué)-54-幾何小實(shí)踐(角的度量)課件滬教版四年級(jí)上冊(cè)數(shù)學(xué)-54-幾何小實(shí)踐(角的度量)課件護(hù)珠斜塔護(hù)珠斜塔：上海市松江天馬山護(hù)珠塔，比比薩斜塔早建近百年。目前此塔向東偏離2.28米、傾斜度6.63度、超過(guò)傾斜度5.2度的比薩斜塔一度多，據(jù)說(shuō)，當(dāng)?shù)氐娘L(fēng)向大都由東南吹來(lái)，風(fēng)力正頂著傾斜的塔身，這就是此塔長(zhǎng)傾不倒的主要原因。護(hù)珠斜塔護(hù)珠斜塔：上海市松江天馬山護(hù)珠塔，比比薩斜塔早建近百

比薩斜塔1990年停止向游人開(kāi)放時(shí)，傾斜角度約5.3°

，2001年修復(fù)后重新開(kāi)放時(shí)，傾斜角度約3.9°

。意大利政府稱(chēng)，可繼續(xù)維持300年不倒。你知道嗎？比薩斜塔1990年停止向游人開(kāi)放時(shí)，傾斜椅子的靠背總是往后傾。用于學(xué)習(xí)的椅子，一般后傾8度；吃飯的椅子，一般后傾9度；沙發(fā)靠背則后傾11度左右。

椅子的靠背總是往后傾。用于學(xué)習(xí)的椅子，一般后傾8度；吃飯的椅山地車(chē)的車(chē)架構(gòu)造特殊，車(chē)座和操作控制梁的角度在71—74度之間，這個(gè)角度讓人騎起來(lái)比較舒服。

山地車(chē)的車(chē)架構(gòu)造特殊，車(chē)座和操作控制梁的角度在71—74度之打羽毛球時(shí)，應(yīng)注意45度角度。

打羽毛球時(shí)，應(yīng)注意45度角度。我們游泳劃水時(shí)手掌角度在20到45度之間最好。我們游泳劃水時(shí)手掌角度在20到45度之間最好。

發(fā)射角度是42.4°，因?yàn)樗憟?chǎng)就位于42.4度左右。這樣，飛船每次經(jīng)過(guò)42.4度時(shí)，就通過(guò)著陸場(chǎng)，使飛船每天至少有一次返回的機(jī)會(huì)。發(fā)射角度是42.4°，因?yàn)樗憟?chǎng)就位于42.4度滬教版四年級(jí)上冊(cè)數(shù)學(xué)-54-幾何小實(shí)踐(角的度量)課件滬教版四年級(jí)上冊(cè)數(shù)學(xué)-54-幾何小實(shí)踐(角的度量)課件1212猜一猜，∠1和∠2誰(shuí)大？12∠2﹥∠1猜一猜，∠1和∠2誰(shuí)大？12∠2﹥∠121221212∠2比∠1大多少度？★∠2和∠1分別包含了多少個(gè)1°角12∠2比∠1大多少度？★∠2和∠1分別包含了多少個(gè)1°21∠2比∠1大多少度？10°10°10°10°10°10°10°∠2比∠1大10度！0°10°20°30°0°10°20°30°40°∠1=30°∠2=40°21∠2比∠1大多少度？10°10°10°10°10°101313310°10°10°10°10°10°10°10°10°10°10°10°10°10°10°10°∠3=160°0°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°310°10°10°10°10°10°10°10°10°10310°10°10°10°10°10°10°10°10°10°10°10°10°10°10°10°0°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°10°10°170°180°310°10°10°10°10°10°10°10°10°100°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°0°10°20°30°40°50°60°70°80°90°1120°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°∠1=30°我知道了！∠2是140°！10°10°10°10°0°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°10°0°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°∠2=40°30°120°10°20°30°40°50°60°70°80°900°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°10°0°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°210°10°20°30°40°50°60°70°80°90°1AOB∠AOB=60°0°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°10°0°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°AOB∠AOB=60°0°10°20°30°40°50°600°10°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°10°0°20°30°40°50°60°70°80°90°100°110°120°130°140°150°160°170°180°COD0°10°20°30°40°50°60°70°80°90°1COD∠COD=65°COD∠COD=65°量角器中心零刻度線(xiàn)零刻度線(xiàn)量角器中心零刻度線(xiàn)零刻度線(xiàn)合作學(xué)習(xí)1、完成練習(xí)一，組內(nèi)交流測(cè)量的方法和結(jié)果合作學(xué)習(xí)1、完成練習(xí)一，組內(nèi)交流測(cè)量的方法和結(jié)果AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB50你會(huì)量出下圖中∠AOB的度數(shù)嗎？AOB50判斷1∠1=20°∠1=15°判斷1∠1=20°∠1=15°判斷BOC∠BOC=145°判斷BOC∠BOC=145°判斷5∠5=135°∠5=125°判斷5∠5=135°∠5=125°這個(gè)角磨損了，聰明的你有辦法知道它原來(lái)的角度嗎？原來(lái)是50°這個(gè)角磨損了，聰明的你有辦法知道它原來(lái)的角度嗎？原來(lái)是50猜一猜，下面的角可能是多少度？猜一猜，下面的角可能是多少度？猜一猜，下面的角可能是多少度？猜一猜，下面的角可能是多少度？合作學(xué)習(xí)1、嘗試完成練習(xí)二，如果遇到困難，可請(qǐng)教學(xué)習(xí)同伴或老師？2、完成后在組內(nèi)交流，你測(cè)量的結(jié)果是多少？你是怎么測(cè)量的？你們的測(cè)量方法有哪些相同點(diǎn)和不同點(diǎn)？合作學(xué)習(xí)1、嘗試完成練習(xí)二，如果遇到困難，可請(qǐng)教學(xué)83°比一比，誰(shuí)能估得又對(duì)又快？83°比一比，誰(shuí)能估得又對(duì)又快？68°比一比，誰(shuí)能估得又對(duì)又快？68°比一比，誰(shuí)能估得又對(duì)又快？146°比一比，誰(shuí)能估得又對(duì)又快？146°比一比，誰(shuí)能估得又對(duì)又快？

放風(fēng)箏比賽時(shí)，規(guī)定用30米長(zhǎng)的線(xiàn)。比哪個(gè)風(fēng)箏放得高？該怎么辦呢？

只要把每根風(fēng)箏線(xiàn)的一端固定在地面上，分別量出它們與地面所形成的角的度數(shù)。你知道嗎？放風(fēng)箏比賽時(shí)，規(guī)定用30米長(zhǎng)的線(xiàn)。比哪個(gè)風(fēng)箏放得高？該怎滬教版四年級(jí)上冊(cè)數(shù)學(xué)-54-幾何小實(shí)踐(角的度量)課件滬教版四年級(jí)上冊(cè)數(shù)學(xué)-54-幾何小實(shí)踐(角的度量)課件護(hù)珠斜塔