当时钟是1点45分时,分针和时针所成的钝角是_ 度.

问题描述:

当时钟是1点45分时,分针和时针所成的钝角是______ 度.

(360°÷60)×[20+(5÷60)×45],
=6°×[20+

1
12
×45],
=6°×[20+3.75],
=6°×23.75,
=142.5°
答:分针和时针所成的钝角是142.5 度.
故答案为:142.5.