單項選擇題
A.350° B.50°右 C.50°左 D.290°右
A.在SE半圓,圓周度數(shù)等于180°減去半圓度數(shù) B.在NE半圓,圓周度數(shù)等于360°減去半圓度數(shù) C.在SW半圓,圓周度數(shù)等于180°減去半圓度數(shù) D.在NW半圓,圓周度數(shù)等于270°加上半圓度數(shù)
A.30° B.030° C.270° D.390°
A.150° B.330° C.090° D.060°
A.30° B.90° C.030° D.090°