【单选题】
正四棱锥底面边长是2,高是1,则斜高是()
①
<img class="kfformula" src="20190809/1565327137897917.png" data-latex="\sqrt {2}"/>
②
<img class="kfformula" src="20190809/1565327137411071.png" data-latex="\sqrt {5}"/>
③
<img class="kfformula" src="20190809/1565327137707931.png" data-latex="2"/>
④
<img class="kfformula" src="20190809/1565327137840495.png" data-latex="\sqrt {3}"/>
【单选题】
标注两个直径均为20的圆时,正确的标注方法是( )
①
<imgwidth="52"height="28"src="http://wljy.whut.edu.cn:80/uploadfiles/word/gctx_zk006.files/gctx_zk0062930.png">
②
<imgwidth="63"height="23"src="http://wljy.whut.edu.cn:80/uploadfiles/word/gctx_zk006.files/gctx_zk0063034.png">
③
<imgwidth="66"height="21"src="http://wljy.whut.edu.cn:80/uploadfiles/word/gctx_zk006.files/gctx_zk0063138.png">
④
<imgwidth="63"height="25"src="http://wljy.whut.edu.cn:80/uploadfiles/word/gctx_zk006.files/gctx_zk0063242.png">