16.
如图,点A、O、E在同一直线上,∠AOB=40°,∠EOD=28°46′,OD平分∠COE,则∠COB的度数为( )
| A. | 57°32′ | B. | 82°28′ | C. | 111°14′ | D. | 125°37′ |
14.计算:(-3)×(-$\frac{1}{3}$)=( )
| A. | -1 | B. | 1 | C. | -9 | D. | 9 |
10.
如图,PA、PB是⊙O的两条切线,A、B为切点,C为优弧BA上一动点.若OA=15,sin∠C=$\frac{4}{5}$,则S△PAB的值为( )
| A. | 108 | B. | 150 | C. | 300 | D. | 192 |
8.
如图,已知?ABCD三个顶点坐标是A(-1,0)、B(-2,-3)、C(2,-1),那么第四个顶点D的坐标是( )
| A. | (3,1) | B. | (3,2) | C. | (3,3) | D. | (3,4) |
7.下列计算正确的是( )
0 293982 293990 293996 294000 294006 294008 294012 294018 294020 294026 294032 294036 294038 294042 294048 294050 294056 294060 294062 294066 294068 294072 294074 294076 294077 294078 294080 294081 294082 294084 294086 294090 294092 294096 294098 294102 294108 294110 294116 294120 294122 294126 294132 294138 294140 294146 294150 294152 294158 294162 294168 294176 366461
| A. | 3a2-2a2=1 | B. | a2•a3=a6 | C. | 2a•3a2=6a3 | D. | (2a2)3=2a6 |