The diameter of the moon is approximately 2,160 miles. Its average distance from earth is approximately 236,000 miles. Consider the angle $\theta$ at the tip of the isosceles triangle formed by your eyes, and the North and South extremities of the moon. It is approximately minutes of degree. (We say that the moon subtends the angle $\theta$.)
The diameter of the sun is approximately 864,000 miles. Its average distance from earth is approximately 92,900,000 miles. It subtends an angle of minutes of degree.
Hint: Draw the height in that isosceles triangle and compute the angle at the top of the triangle. Multiply with 2. A degree has 60 minutes of degree.