40,075 km

Also, how many miles is it around the Earth once? 24,901 miles

Considering this, what are the dimensions of the earth?

Because of this, the diameter of the Earth at the equator is about 43 kilometers (27 mi) larger than the pole-to-pole diameter. As a result, the latest measurements indicate that the Earth has an equatorial diameter of 12,756 km (7926 mi), and a polar diameter of 12713.6 km (7899.86 mi).

What is Earth made of?

The Earth is made out of many things. Deep inside Earth, near its center, lies Earths core which is mostly made up of nickel and iron. Above the core is Earths mantle, which is made up of rock containing silicon, iron, magnesium, aluminum, oxygen and other minerals.