18.下图四张扑克牌中,图案属于中心对称的是( )
| A. | B. | C. | D. |
17.
如图,△ABC中,∠A=36°,AB=AC,BD平分∠ABC,下列结论错误的是( )
| A. | ∠C=2∠A | B. | BD=BC | ||
| C. | △ABD是等腰三角形 | D. | 点D为线段AC的中点 |
15.设a=-2×42,b=-(2×4)2,c=-(2-4)2,则a,b,c的大小关系为( )
| A. | a<b<c | B. | b<a<c | C. | c<b<a | D. | c<b<a |
14.三角形的三条边长分别为a,b,c,满足等式(a+b)2-c2=2ab,则此三角形是( )
0 286805 286813 286819 286823 286829 286831 286835 286841 286843 286849 286855 286859 286861 286865 286871 286873 286879 286883 286885 286889 286891 286895 286897 286899 286900 286901 286903 286904 286905 286907 286909 286913 286915 286919 286921 286925 286931 286933 286939 286943 286945 286949 286955 286961 286963 286969 286973 286975 286981 286985 286991 286999 366461
| A. | 锐角三角形 | B. | 等边三角形 | C. | 直角三角形 | D. | 钝角三角形 |