7.
如图,在△ABC中,D,E,F分别为BC,AC,AB边的中点,AH⊥BC于H,FD=8,则HE等于( )
| A. | 20 | B. | 16 | C. | 12 | D. | 8 |
3.已知三角形ABC三个顶点的坐标是A(-2,1),B(2,3),C(1,-2),将三角形ABC进行平移,不能得到三角形A1B1C1(相同字母的点是对应点)的是( )
| A. | A1(-2,-1),B1(2,1),C1(1,-4) | B. | A1(-1,1),B1(3,3),C1(2,-2) | ||
| C. | A1(0,0),B1(4,2),C1(3,-3) | D. | A1(-1,2),B1(3,4),C1(2,-3) |
2.若点A的坐标为($-\frac{7}{2}$,0),它到x轴上一点B的距离是$\frac{9}{2}$,则点B的坐标是( )
| A. | (1,0) | B. | (-8,0) | C. | (1,0)或(-8,0) | D. | (-1,0) |
1.
如图,直线l1∥l2,则∠a的度数是( )
| A. | 120° | B. | 130° | C. | 140° | D. | 150° |
20.在实数$\root{3}{-27}$,0.101 001 0001,π,$\sqrt{5}$中,无理数有( )
0 307509 307517 307523 307527 307533 307535 307539 307545 307547 307553 307559 307563 307565 307569 307575 307577 307583 307587 307589 307593 307595 307599 307601 307603 307604 307605 307607 307608 307609 307611 307613 307617 307619 307623 307625 307629 307635 307637 307643 307647 307649 307653 307659 307665 307667 307673 307677 307679 307685 307689 307695 307703 366461
| A. | 1个 | B. | 2个 | C. | 3个 | D. | 4个 |