Answer:
blank A->(Law of cosines)
blank B->(Pythagorean theorem/theory)
Explanation:
Reason to get the correct measurement's of angles in a figure you must apply Cosines or Law of Cosines(same thing) which simply means angle edges
and to get the measurements of the angles length use the Pythagorean theorem which is (a²+b²=c²)
- Hope I was helpful in any way thanks and sorry