An astronomer knows the distances from herself to stars AAA and BBB, as well as the distance between them. The distances are 450450450, 400400400, and 909090 light years (\text{l. y.}l. y.start text, l, point, y, point, end text) respectively. If the astronomer's telescope is currently pointed at star AAA, how many degrees must she rotate her telescope to see star BBB?

Do not round during your calculations. Round your final answer to the nearest degree.