The Equator is between the Tropic of Capricorn and the Tropic of Cancer.
The Tropics
tropical regions
at the center of the earth
at the center of the earth
The geographic center of the USA, including the lower 48, Alaska, and Hawaii. A bit awkward, perhaps. The geographic center for the lower 48 is marked with a monument in Kansas, and the geographic center of North America is also marked by a monument in North Dakota.
about 3238 miles
Great Valley
With a center punch and hammer.
Multiply the diameter by (pi), or the radius by (2 pi). If you have a drawing of the circle, and the center is marked, you can measure the radius and the diameter. Just lay your ruler across the circle, and make sure that it touches the center. If the center isn't marked, then it won't be that easy.
This is the 'convergence' or meeting point of two air masses in between the two tropics. This is the point where the two Hadley cells meet. This is marked by an area of low pressure.
On my map, the Brisbane city center is marked at 27
tropic of cancer