1 time deal... or... 70 times?

來源: 於 2012-01-01 14:40:53 [舊帖] [給我悄悄話] 本文已被閱讀：次

AB=AC...

that means angle ACB equal to B. so after the first time, it will bounce off the region?

If AB=BC then it would be different story. :)

it will need 35 times to make the reflection angle grow to 89.73 degree(add 1.994 to 19.94 for 35 times). need another 35 times to make it increase to (180- 20.48) degree(keep adding 1.994 to it). then the next time it will be more than (180-19.94). So there will be 70 times.