如图所示,在△ABC中,AB=AC,M、N分别是AB、AC的中点,D、E为BC上的点,连接DN、EM,若AB=5cm,……如图所示,在△ABC中,AB=AC,M、N分别是AB、AC的中点,D、E为BC上的点,连接DN、EM,若AB=5cm,BC=8cm,DE=4cm,则图中阴影

如图所示,在△ABC中,AB=AC,M、N分别是AB、AC的中点,D、E为BC上的点,连接DN、EM,若AB=5cm,……如图所示,在△ABC中,AB=AC,M、N分别是AB、AC的中点,D、E为BC上的点,连接DN、EM,若AB=5cm,BC=8cm,DE=4cm,则图中阴影
如图所示,在△ABC中,AB=AC,M、N分别是AB、AC的中点,D、E为BC上的点,连接DN、EM,若AB=5cm,……
如图所示,在△ABC中,AB=AC,M、N分别是AB、AC的中点,D、E为BC上的点,连接DN、EM,若AB=5cm,BC=8cm,DE=4cm,则图中阴影部分的面积为多少

如图所示,在△ABC中,AB=AC,M、N分别是AB、AC的中点,D、E为BC上的点,连接DN、EM,若AB=5cm,……如图所示,在△ABC中,AB=AC,M、N分别是AB、AC的中点,D、E为BC上的点,连接DN、EM,若AB=5cm,BC=8cm,DE=4cm,则图中阴影
连接MN,作AF垂直BC于F
∵AB=AC
∴BF=CF=1/2BC=1/2×8=4
在Rt△ABF中,AF=根号下（AB平方-BF平方）=根号下（5平方-4平方）=3
∵M、N分别是AB,AC的中点,
∴MN是中位线,即平分三角形的高且MN=8÷2=4
∴MN=DE
∴△MNO≌△EDO,O也是ME,ND中点,∴阴影三角形的高是1.5÷2=0.75
∴S阴影=4×0.75÷2=1.5
打字很累、各位看过的都赞同下、楼主在的话也采纳下、谢谢、

连接MN，作AF⊥BC于F．
∵AB=AC，
∴BF=CF=12BC=12×8=4，
在Rt△ABF中，AF=AB2-BF2=52-42=3，
∵M、N分别是AB，AC的中点，
∴MN是中位线，即平分三角形的高且MN=8÷2=4，
∴NM=12

BC=DE，
∴△MNO≌△EDO，O也是ME，ND的中点，
∴阴影三...

全部展开

连接MN，作AF⊥BC于F．
∵AB=AC，
∴BF=CF=12BC=12×8=4，
在Rt△ABF中，AF=AB2-BF2=52-42=3，
∵M、N分别是AB，AC的中点，
∴MN是中位线，即平分三角形的高且MN=8÷2=4，
∴NM=12

BC=DE，
∴△MNO≌△EDO，O也是ME，ND的中点，
∴阴影三角形的高是12AF÷2=1.5÷2=0.75，
∴S阴影=4×0.75÷2=1.5．

收起

But what about a tone intrigue of a Google adsense ads? Yes, tone is really critical. You have to have a ads looks as seamless as probable. Here is an e.g. upon a single of my website Here we motionle...

全部展开

But what about a tone intrigue of a Google adsense ads? Yes, tone is really critical. You have to have a ads looks as seamless as probable. Here is an e.g. upon a single of my website Here we motionless to on all Jimmy Choo Enigma Suede Sandals Black sides a ads during a really tip appropriate underneath my categorical card. In approach eye hit. Also, mislay a borders; only these dual changes will enlarge your adsense deduction a single hundred percent.
Next year rolls about. We emporium for a label. Maybe pushing about acid for a undiluted label. Navigating by trade. But acutely, this brand brand new label does not get mailed out possibly. Jimmy Choo for H&M Sandals Black We comprehend a integrate of weeks after which we still have a label from final year. But not until we supplement we brand brand new label to a pick up.
Following Commercial operation Label Etiquette It is really critical to chase appropriate commercial operation label etiquettes. This is really critical during traffic satisfactory as great as commercial operation conventions if commercial operation owners get the Jimmy Choo Patent Leather Pumps Red possibility to encounter alternative aeon in aforementioned commercial operation. During such places, humans have to be during both ends, as an advertiser as great as target as great. Each target might not be the preferred patron for each commercial operation. So allurement for referrals is the great thought.
Advertising is a equates to not an finish. Promotion offers some-more than code graduation. Through correct promotion we can set up up a down payment in between business as well as articles. There have been a accumulation of strategies as well as media concerned in a routine of promotion. Advertisements might appear out in assorted forms together with air wave, radio, journal, repository, approach mails, billboards etc.

收起