Answer: [tex]87^{\circ}[/tex]
Step-by-step explanation:
Because an angle inscribed in a semicircle is a right angle, [tex]\angle B=90^{\circ}[/tex]
So, as angles in a triangle add to 180 degrees, [tex]\angle A=180^{\circ}-90^{\circ}-3^{\circ}=\boxed{87^{\circ}}[/tex]
