when were the pyramids built

The Egyptian pyramids are ancient pyramid-shaped masonry structures located in Egypt.

There are 138 pyramids discovered in Egypt as of 2008. Most were built as tombs for the country's Pharaohs and their consorts during the Old and Middle Kingdom periods.

The earliest known Egyptian pyramids are found at Saqqara, northwest of Memphis. The earliest among these is the Pyramid of Djoser (constructed 2630 BC–2611 BC) which was built during the third dynasty. This pyramid and its surrounding complex were designed by the architect Imhotep, and are generally considered to be the world's oldest monumental structures constructed of dressed masonry. The estimate of the number of workers to build the pyramids range from a few thousand, twenty thousand, and up to 100,000

where is great wall of china

The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China in part to protect the Chinese Empire or its prototypical states against intrusions by various nomadic groups or military incursions by various warlike peoples or forces. Several walls were being built as early as the 7th century BC; these, later joined together and made bigger and stronger, are now collectively referred to as the Great Wall.

why do mountains affect weather

 Mountains:

There are two sides: wayward and leeward.

Wayward: Whenever it is raining, the wayward side gets the rain so there is good soil most of the time. But as the cloud goes up the mountain, it keeps raining until soon there is no more water in the cloud.

Leeward: Now the cloud is at the other side of the mountain. There is no more precipitation so the leeward side of the mountain gets no rain so the flat ground on this side of the mountain is dry and humid.

what is the new planet called

Kepler-186f

The new found planet, called KEPLER-186f, was first spotted by NASA'S KEPLER space telescope and circles a dim red dwarf star about 490 light-years from Earth. 

how far is the planet mars away from earth

The average distance between the Earth and Mars is 225 million km