5.
如图,AB为⊙O的直径,CD为弦,AE=7cm,BE=3cm,∠AED=60°,则弦CD的长为( )
| A. | 2$\sqrt{21}$cm | B. | 4$\sqrt{6}$cm | C. | 2$\sqrt{22}$cm | D. | 8cm |
1.小明与父母从海口乘火车去上海,他们买到的火车票是同一排相邻的三个座位,那么小明恰好坐在父母中间的概率是( )
0 282166 282174 282180 282184 282190 282192 282196 282202 282204 282210 282216 282220 282222 282226 282232 282234 282240 282244 282246 282250 282252 282256 282258 282260 282261 282262 282264 282265 282266 282268 282270 282274 282276 282280 282282 282286 282292 282294 282300 282304 282306 282310 282316 282322 282324 282330 282334 282336 282342 282346 282352 282360 366461
| A. | $\frac{1}{3}$ | B. | $\frac{1}{4}$ | C. | $\frac{1}{2}$ | D. | $\frac{2}{3}$ |