1) You have:
Cos(50°)=adjacent/hypotenuse
Cos(50°)=XY/8
Solve for XY:
XY=8Cos(50°)
XY=8 cm
The answer is 8 cm
2)The angle m∠A is:
Cos^-1(m∠A)=8/15
m∠A=57.76°
The angle m∠C is:
Sin⁻1(m∠C)=8/15
m∠C=32.23°
The approximate difference is:
m∠A-m∠C≈25.53°
The answer is: The approximate difference between m∠A and m∠C is 25.53°.