Substended angle, rotational kinematics

[bulbasaur88]

The moon has a diameter of 3.48 x 10^6 m and is a distance of 3.85 x 10^8m from the earth. The sun has a diameter of 1.39 x 10^9 m and is 1.50 x 10^11 m from the earth.

(a.) What are the angles (in radians) subtended by the moon and the sun, as measured by a person standing on the earth.

Because the large planetary masses are so very far away, we can assume that s = diameter

Θ = s/r

For the moon:
S = 3.48E6 m
r = 3.85E8 m
Θ = s/r = 3.48E6/3.85E8
Θ = 0.009038961 radiansFor the sun:
S = 1.39E9 m
r = 1.50E11 m
Θ = s/r = 1.39E9/1.50E11
Θ = 0.0092666667 radians

(b.) Based on the answers to part (a.), is a total eclipse of the sun really "total"?
No, because the angles are not perfectly equal.

(c.) What is the ratio (as a percentage) of the apparent circular area of the moon to the apparent circular area of the sun?

For part C, do I just use Pi(radius)² and compare the two areas? I just don't understand stand what they mean by "apparent" circular area. Is this problem just to emphasize how much larger the sun is than the moon?

 

[kuruman]

By "apparent" circular area they mean the circular area as it appears to you. Imagine that the moon and the sun as you see them in the sky are two circles on a table in front of you. What will you say the ratio of the areas is?