Two regular pentagons are concentric to each other. One of which has sides of 20 m and the other has sides of 10 m. If their corresponding vertices are in the same direction, find the area inside the larger pentagon but outside the smaller pentagon.

The area bounded by the waterline of a reservoir is determined by using planimeter and the following are the results: A1 = 20,000 m2; A2 = 18,000 m2; A3 = 14,000 m2; A4 = 10,000 m2; and A5 = 8,000 m2. If the contour interval is 2 m, find the capacity of the reservoir (in cubic meter) using end area method.

The magnetic bearing of a line was recorded as S 80° 15' W in 2000 at Mactan Island which had a declination of 16° E in that year. Compute the present magnetic bearing of the same line in 2006 if the declination in 2006 is 4° 30' E.