在直角梯形ABCD中,AD‖BC,角B=90°,AD=24CM,AB=8CM,BC=26CM,动点P从A直角梯形在直角梯形ABCD中,AD//BC,角B=90度,AB=8cm,AD=24cm,BC=26cm,动点P从点A开始沿AD向点D以1cm/s的速度移动,动点Q从点C开始沿CB向B点以3cm/s的
来源：学生作业帮助网 编辑：六六作业网 时间：2024/12/19 14:10:00
在直角梯形ABCD中,AD‖BC,角B=90°,AD=24CM,AB=8CM,BC=26CM,动点P从A直角梯形在直角梯形ABCD中,AD//BC,角B=90度,AB=8cm,AD=24cm,BC=26cm,动点P从点A开始沿AD向点D以1cm/s的速度移动,动点Q从点C开始沿CB向B点以3cm/s的
在直角梯形ABCD中,AD‖BC,角B=90°,AD=24CM,AB=8CM,BC=26CM,动点P从A直角梯形
在直角梯形ABCD中,AD//BC,角B=90度,AB=8cm,AD=24cm,BC=26cm,动点P从点A开始沿AD向点D以1cm/s的速度移动,动点Q从点C开始沿CB向B点以3cm/s的速度,如果P,Q分别从A,C同时出发,设移动时间为t(s).
当T为何值时,PQCD为直角梯形
在直角梯形ABCD中,AD‖BC,角B=90°,AD=24CM,AB=8CM,BC=26CM,动点P从A直角梯形在直角梯形ABCD中,AD//BC,角B=90度,AB=8cm,AD=24cm,BC=26cm,动点P从点A开始沿AD向点D以1cm/s的速度移动,动点Q从点C开始沿CB向B点以3cm/s的
26-3T=t
26=4t
t=6.5
因为要使四边形PQCD为直角梯形，则当连结PQ时，PQ要分别垂直于AD与BC，所以AP=BQ.
所以1t=26-3t
t=6.5
检验：当t=6.5时，
1t=6.5＜24,3t=19.5＜26
所以当t=6.5时，四边形PQCD为直角梯形。
（1）设经过xs，四边形PQCD为平行四边形
即PD=CQ
所以24-x=3x，得x=6．（3分）
（2）设经过ys，四边形PQBA为矩形，
即AP=BQ，所以y=26-3y，得y=13 2 ．（3分）
（3）设经过ts，四边形PQCD是等腰梯形．过Q点作QE⊥AD，过D点作DF⊥BC，
∵四边形PQCD是等腰梯形，
∴PQ=DC．
...
全部展开
（1）设经过xs，四边形PQCD为平行四边形
即PD=CQ
所以24-x=3x，得x=6．（3分）
（2）设经过ys，四边形PQBA为矩形，
即AP=BQ，所以y=26-3y，得y=13 2 ．（3分）
（3）设经过ts，四边形PQCD是等腰梯形．过Q点作QE⊥AD，过D点作DF⊥BC，
∵四边形PQCD是等腰梯形，
∴PQ=DC．
又∵AD∥BC，∠B=90°，
∴AB=QE=DF．
∴△EQP≌△FDC．
∴FC=EP=BC-AD=26-24=2．
又∵AE=BQ=26-3t EP=t-AE，
∴EP=AP-AE=t-（26-3t）=2．
得：t=7．
∴经过7s，四边形PQCD是等腰梯形．
收起
相关的主题文章：
Puma Shoe on sale can used as sports shoes, also can be leasuire shoes. So Puma shoes sale is loved by everyone as their different style in the market. with internatio...
全部展开
相关的主题文章：
Puma Shoe on sale can used as sports shoes, also can be leasuire shoes. So Puma shoes sale is loved by everyone as their different style in the market. with international style. Mens Puma Future Cat shoes develop quickly in the market.
When i have got this Puma Trainers,UGG Gypsy Sandals, I began to love this Puma shoes on sale a lot, but the mainland cannot be bought. There is also a lovely toy Passport cover and Benins passport is the same, but with a condom,Miu Miu Bags, is very interesting. Puma running shoes on sale have some lovely gift, not enumerate.Puma Sneakers is now set to release a new package of cobra which will have a similar colorway, such as styles popular shoe. This new discount puma shoes would be popular in near time.
PUMA shoes sale vibrant and Africa before the series of paintings from the virial selected the seven lively patterns, with their bright, wild, extremely impact of color to the perfect fusion of design and build a brand new Mens Puma Future Cat shoes Activity Africa series.
It is said mens puma shoes on sale join one of the worlds most popular contemporary artists can Hai Ende Virial (Kehinde Wiley),UGG Baby Boots, Introducing the 2010 spring and summer are enlivened Africa series apparel, footwear and accessories.
收起