Answer:
Step-by-step explanation:
Think about a right triangle with legs AB and AC. Then you have ...
AB² +AC² = BC² = 10² = 100
If AB and AC are shorter than that, the sum of their squares will be less than 100. When the legs of a right triangle are shortened, the angle between them must increase in order for them to continue to form a triangle.
The triangle with AB² +AC² < 100 is an obtuse triangle.
__
Conversely, if AB and AC are lengthened so the sum of their squares is greater than 100, the angle between them will have to decrease for them to form a triangle.
The triangle with AB² +AC² > 100 is an acute triangle.
