15.
如图,四边形ABCD中,∠B=60°,∠D=50°,将△CMN沿MN翻折得△EMN,若EM∥AB,EN∥AD,则∠C的度数为( )
| A. | 110° | B. | 115° | C. | 120° | D. | 125° |
14.
如图,正五边形ABCDE内接于⊙O,若⊙O的半径为5,则$\widehat{AB}$的长度为( )
0 294824 294832 294838 294842 294848 294850 294854 294860 294862 294868 294874 294878 294880 294884 294890 294892 294898 294902 294904 294908 294910 294914 294916 294918 294919 294920 294922 294923 294924 294926 294928 294932 294934 294938 294940 294944 294950 294952 294958 294962 294964 294968 294974 294980 294982 294988 294992 294994 295000 295004 295010 295018 366461
| A. | π | B. | 2π | C. | 5π | D. | 10π |