问题:
同弧所对的圆周角______;同弧所对的圆周角是圆心角的______;半圆(或直径)所对的圆周角是______,90°的圆周角所对的弦是______.
同弧所对的圆周角______;同弧所对的圆周角是圆心角的______;半圆(或直径)所对的圆周角是______,90°的圆周角所对的弦是______.
参考答案: