Answer:
A. Yes, angle A is the right angle.
Explanation:
Remember a right angle triangle can be solved using the right -angle theorem.
A²= B²+C²
let's observe that AB² + CA² = BC²
i.e ( 5√3)² + 5²= 10²
75 + 25 = 100
Making BC the hypotenuse and the angle facing the hypotenuse is angle a which is a right angle