6.
如图,OC是∠AOB的角平分线.D,E分别是OA,OB上的点,则下列条件中不能判定△OCD与△OCE全等的是( )
| A. | ∠OCD=∠OCE | B. | CD⊥OA,CE⊥OB | C. | OD=OE | D. | CD=CE |
5.
如图表示的是不等式组( )的解集.
| A. | $\left\{\begin{array}{l}{x≤1}\\{x<-2}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{x≤1}\\{x>-2}\end{array}\right.$ | C. | $\left\{\begin{array}{l}{x≥1}\\{x<-2}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{x≥1}\\{x>-2}\end{array}\right.$ |
4.将△AOB绕点O按逆时针方向旋转45°后得到△COD,若∠AOB=27°,则∠BOC的度数是( )
| A. | 18° | B. | 27° | C. | 45° | D. | 72° |
3.若x>y,则下列各式变形正确的是( )
| A. | x-6<y-6 | B. | $\frac{x}{2}$<$\frac{y}{2}$ | C. | 2x+1>2y+1 | D. | -x>-y |
1.
如图,在等腰直角△ABC中,∠C=90°,点O是AB的中点,且AB=$\sqrt{6}$,将一块直角三角板的直角顶点放在点O处,始终保持该直角三角板的两直角边分别与AB、BC相交,交点分别为D、E,则CD+CE=( )
| A. | $\sqrt{3}$ | B. | $\sqrt{2}$ | C. | 2 | D. | $\sqrt{6}$ |
19.
如图,直线l1∥l2,若∠1=130°,∠2=60°,则∠3=( )
| A. | 50° | B. | 60° | C. | 70° | D. | 80° |
17.下列长度的三条线段能组成锐角三角形的是( )
0 295011 295019 295025 295029 295035 295037 295041 295047 295049 295055 295061 295065 295067 295071 295077 295079 295085 295089 295091 295095 295097 295101 295103 295105 295106 295107 295109 295110 295111 295113 295115 295119 295121 295125 295127 295131 295137 295139 295145 295149 295151 295155 295161 295167 295169 295175 295179 295181 295187 295191 295197 295205 366461
| A. | 2,3,3 | B. | 2,3,4 | C. | 2,3,5 | D. | 3,4,5 |