90th meridian east

Okay, so let's talk about what a meridian is first. You know how you live on Earth, right? Well, Earth is a big round ball (we call it a sphere). And when you look at Earth from space, you can see that there are lines that go from the North Pole all the way down to the South Pole. These lines are called meridians, and they help us figure out where we are on Earth.

Now, the 90th meridian east is a special meridian that runs from the North Pole down to the South Pole, but it goes through a specific point on Earth. That point is located 90 degrees east of the Prime Meridian, which is another special meridian that runs through Greenwich, England.

When we talk about degrees on a meridian, we are measuring how far away a certain point is from the North or South Pole. So when we say that the 90th meridian east is at 90 degrees east of the Prime Meridian, we mean that it's really far away from the Prime Meridian and that it's on the other side of the world (if you were to dig a hole through the Earth and come out on the other side, you would be at the 90th meridian east).

Lots of countries and places on Earth are located along the 90th meridian east, including India, China, and Thailand. In fact, the 90th meridian east runs right through the middle of some of these countries, so it's really important for figuring out where exactly you are in the world.