Latitude Lines Count on a Globe

This question asks us to find the total number of distinct parallels of latitude that can be identified on a standard globe. We need to consider only those lines drawn at integer degree intervals and specifically exclude the North and South Poles themselves.

Understanding Parallels of Latitude

Parallels of latitude are imaginary circles drawn around the Earth parallel to the Equator. They help us measure the distance north or south of the Equator. Latitude is measured in degrees, ranging from 0° at the Equator to 90° North at the North Pole and 90° South at the South Pole.

Identifying Latitude Lines at Integer Degrees

The question specifies using only integer degree intervals. Let's break down how these lines are counted:

• The latitude scale runs from 0° to 90° in the Northern Hemisphere and 0° to 90° in the Southern Hemisphere.
• The Equator represents 0° latitude. This is one distinct parallel.
• In the Northern Hemisphere, the parallels of latitude at integer degrees are 1°, 2°, 3°, ..., up to 89°. The 90° N parallel is the North Pole, which must be excluded according to the question. So, there are 89 integer-degree latitude lines north of the Equator.
• Similarly, in the Southern Hemisphere, the parallels of latitude at integer degrees are 1°, 2°, 3°, ..., up to 89°. The 90° S parallel is the South Pole, which also must be excluded. So, there are 89 integer-degree latitude lines south of the Equator.

Calculating Total Integer Latitude Lines

To find the total number of such latitude lines, we sum the lines from the Northern Hemisphere, the Southern Hemisphere, and the Equator:

Number of lines North of Equator (excluding North Pole): 89

Number of lines South of Equator (excluding South Pole): 89

The Equator (0° latitude): 1

The total count is the sum of these three parts:

$$ \text{Total Lines} = (\text{Lines North}) + (\text{Lines South}) + (\text{Equator}) $$

$$ \text{Total Lines} = 89 + 89 + 1 $$

$$ \text{Total Lines} = 179 $$

Conclusion on Latitude Lines

Therefore, considering only distinct parallels of latitude drawn at integer degree intervals and excluding the North and South Poles, there are a total of 179 such latitude lines that can be identified on a standard globe.