5.
如图,已知直线a与b相交,若∠1=75°,则∠2的度数为( )
| A. | 75° | B. | 105° | C. | 115° | D. | 无法确定 |
4.下列说法中正确的是( )
| A. | 对顶角相等 | B. | 有一条公共边的两个角互补 | ||
| C. | 相等的两个角是对顶角 | D. | 互补的两个角是邻补角 |
19.计算$\sqrt{\frac{1}{2}ab}•\sqrt{\frac{1}{6}a}$的最终结果是( )
| A. | $\frac{1}{12}|a|b$ | B. | |a|$\sqrt{\frac{b}{12}}$ | C. | $\frac{a\sqrt{3b}}{6}$ | D. | -$\frac{a\sqrt{3b}}{6}$ |
18.已知$\sqrt{12a}$是整数,则正整数a的最小值是( )
0 282112 282120 282126 282130 282136 282138 282142 282148 282150 282156 282162 282166 282168 282172 282178 282180 282186 282190 282192 282196 282198 282202 282204 282206 282207 282208 282210 282211 282212 282214 282216 282220 282222 282226 282228 282232 282238 282240 282246 282250 282252 282256 282262 282268 282270 282276 282280 282282 282288 282292 282298 282306 366461
| A. | 2 | B. | 3 | C. | 6 | D. | 12 |