Bài tập về Hình vuông Lớp 8

Bài 1: Tính độ dài đường trung tuyến ứng với cạnh huyền của một tam giác vuông có hai cạnh góc vuông bằng 4cm và 3cmBài 2:Cho tam giác ABC đường cao AH.Gọi I là trung điểm của AC, E đối xứng H qua I. Tứ giác AHCE là hình gì? Vì sao?Bài 3:Cho tứ giác ABCD.Gọi E, F,G,H lần lượt là trung điểm của AB,BC,CD,DA. Tứ giác EFGH là hình gì? Vì sao?Bài 3:Cho tứ giác ABCD.Gọi E, F,G,H lần lượt là trung điểm của AB,BC,CD,DA. a)Tứ giác EFGH là hình gì? Vì sao?b) Tìm điều kiện của tứ giác ABCD để tứ giác EFGH là hình chữ nhậtBTVN: 112,115,116 trang 94 SBTDesigner helps you get your point acrossPowerPoint Designer suggests professional designs for your presentation, based on the content in your slides. Designer is a subscription-only feature. If you have an Office 365 subscription, the next slide shows you how it works in a new presentation.How to use PowerPoint DesignerHow it works:1Start a new presentation by going to File > New > Blank Presentation.2On the very first slide, add a picture: Go to Insert > Pictures or Insert > Online Pictures and choose the picture.Hint: You need to be online when you add the picture.3When PowerPoint asks your permission to get design ideas, select Let's Go.4Choose a design you like from the Design Ideas task pane.MorphMorph makes smooth animations and object movements in your presentation. You use two similar slides to perform the animation, but it looks to your audience like the action happens on one slide. Play the video on the right to see a quick example.Morph is a subscription-only feature. If you have an Office 365 subscription, you can try it yourself with the steps on the next slide.Setting up MorphTry it yourself with these two simple “planets”:1Duplicate this slide: Right-click the slide thumbnail and select Duplicate Slide.2In the second of these two identical slides, change the shapes on the right in some way (move, resize, change color), then go to Transitions > Morph.3Return to the first of the two slides and press Slide Show button and then select Play to see your circle morph!Hint: Effect Options gives you even more options for Morph.Working together in real timeWhen you share your presentation with others, you’ll see them working with you at the same time. How it works:1Select Share from above the ribbon, or by using short-key Alt-ZS, to invite people to work with you (You can save to the cloud at this point.)2When other people are in the presentation, a marker shows who is on which slide 3 and the part of the slide they're editing.You’re an expert with Tell MeThe Tell Me box finds the right command when you need it, so you can save time and focus on your work.Try it:1Select the Robot picture on the right.SELECT ME2Type animation in the Tell Me box, and then choose Add Animation.3Choose an animation effect, like Zoom, and watch what happens.Explore without leaving your slidesSmart Lookup brings research directly in to PowerPoint.Try it:1Right-click in the word office in the following phrase: office furniture2Choose Smart Lookup, and notice that results are contextual for that phrase, not Microsoft Office apps.3Just for fun, try Smart Lookup again by right-clicking in the word Office in Step 2.More questions about PowerPoint?Select the Tell Me button and type what you want to know.Visit the PowerPoint team blogGo to free PowerPoint trainingGive feedback about this tourSELECT THE ARROW WHEN IN SLIDE SHOW MODE