Answer:
22.5deg, 45deg, 112.5deg, an obtuse triangle.
Step-by-step explanation:
The sum of angles is 180deg.
If they're in the ratio of 1:2:5, one angle is 1/(1+2+5)=1/8 of 180deg, the others are 2/8 and 5/8, so:
Smallest angle is 180deg * 1/8 = 22.5deg
Second is 180deg * 2/8 = 45deg
Third is 180deg * 5/8 = 112.5deg
it's an obtuse triangle, as it has an angle over 90deg
