The Great Pyramid is the biggest of the three, with an average length of each side at the base of 755.75 feet (230 metres) and an initial height of 481.4 feet (147 metres). Its sides are aligned with the cardinal directions for astronomical observation and there are evidence that they were painted red during certain periods of their history.

Including its limestone casing, the pyramid weighs about 2.7 million pounds (1.25 billion grams). It is currently the only surviving monument from the Ancient Egypt's Old Kingdom period (2690-2160 B.C.), when the pyramids were first built. The Great Pyramid was probably built by King Khufu (also known as Cheops), who lived approximately 495 B.C. to 405 B.C. It is believed that he used over 600,000 limestone blocks to build his pyramid.

With **its appearance** in **ancient Egyptian art**, the Great Pyramid has always held a special place in the culture. It was here that Egyptians looked up at the night sky to track the movements of the Sun during the annual cycle of sunlight and darkness. They also used the pyramid as a tool to measure time accurately for **religious rituals** and calendar purposes. After the pharaohs, the pyramid became a symbol of power and authority and was often used as a palace or temple building.

62.5 feet The pyramid originally stood 62.5 meters (205 feet) tall, with a base measuring 109 meters (358 feet) by 121 meters (397 feet) and was coated in polished white limestone. The original pyramid was destroyed around 843 AD during an earthquake.

The Great Pyramid of Giza is the best-known example of a step pyramid. It is estimated to have been built for Pharaoh Khufu about 2560 BC. The pyramid is named after its resemblance to a giant step. It has three main levels: a lower, middle, and upper. The lowest level consists of a horizontal platform that is divided into four parts by parallel lines of red granite blocks. On top of this floor are laid **two large slabs** of black stone, which are also divided into four parts by more lines of granite blocks. On these four parts sit four more huge stones, each weighing about 200 tons. They are called "stepped stones" and they form the upper part of the pyramid. The overall height of the pyramid including its capstone is estimated to be 146 feet (45 m).

It is one of **the largest buildings** in **human history**. Its size alone makes it worthy of attention. However, what makes the Great Pyramid truly remarkable is not only its size, but also its design and construction.

The group's northernmost and oldest pyramid was erected for Khufu (Greek: Cheops), the fourth dynasty's second monarch. It is also the highest, with a peak elevation of 2,330 feet (723 metres).

The group's central pyramid was built for Pharaoh Snefru (pronounced "snafur"). The pyramid is nearly half as big as Khufu's, with **an average length** of each side at the base of **454.50 feet** (137 metres) and an initial height of 347.0 feet (106 metres). It reaches **a maximum height** of 226.5 feet (69 metres).

The smallest pyramid is that of King Zoser. It has an average length of each side at the base of 565.25 feet (169 metres) and an initial height of 381.5 feet (115 metres). It reaches a maximum height of 205.5 feet (62 metres).

All three pyramids are made of limestone, which was easily available in Giza at the time they were built. The stones were brought from nearby quarries to **the building sites** by tens of thousands of laborers over an extensive area.

The pyramid is therefore 400 cubits per side by 280 high in ancient Egyptian measurement. Mathematically, there is a link between the length of the base and the height of one side: 1.25, a ratio that the makers, of course, have perfected. The base of a pyramid is always larger than its height, but the ratio between them is almost exactly the same as that of a square pyramid.

In terms of volume, the pyramid is about 24 million cubic feet. This is less than one-tenth the size of the Great Pyramid at Giza in Egypt or Mount Rushmore in **South Dakota**.

A pyramid's volume can be calculated from its height and base using this formula: V = 1/2bh3. Here b means "base" and h means "height". Volumes of other shapes, such as spheres or cubes, can be found using similar formulas. For example, to find the volume of a sphere, just use the formula V = 4/3πr3 where r is the radius of the sphere.

It takes a lot of stone to build a pyramid! There are various estimates of how much stone was used in building the pyramids, but all agree that it is a very large amount. One estimate is that there are about 7 million stones in **each pyramid** (this includes **some debris** left over from construction). This would mean that they were built **one stone** at a time.

The Great Pyramid of Giza is massive, reaching **756 feet** at its base and 455 feet in height. In fact, the pyramids are large enough to be viewed from space on clear days. Satellite images show that they remain white, even during rainy periods, because their granite blocks were carefully chosen and cut to **a perfect angle** of repose.

The pyramid shape is ideal for solar power generation. The sun's energy can be collected by reflecting sunlight onto the top of the pyramid where it is absorbed by the stone or glass used to cover it. This process generates electricity, which is then stored in a battery for use at night or on cloudy days. The Egyptians built their own power station using this technology and they still do today: solar power stations. They are located on the rooftops of some private homes near the pyramids at Giza.

In addition to being beautiful objects in themselves, the pyramids serve as important landmarks. Their size makes them visible from far away, which is why astronauts have visited them before. And since they're made of solid rock, they'll always be there long after the people who built them are gone.

The Great Pyramid took about 20 years to complete. The pyramid's base was designed to be 756 feet wide. It is estimated that there were at least 2,000 people involved in **its construction**.

Pyramids were built by many cultures over an extremely large area of the world - from Egypt all the way through to Mexico. Because of this, it is difficult to give an exact time requirement for their construction. However, it takes on average about three years to build a side at **most pyramids**.

In addition to being a monumental building, the Great Pyramid was also used for storing valuables and serving as a temple. It has been suggested that priests carried out rituals within the pyramid to offer prayers on behalf of those who had been buried there.

Construction of the Great Pyramid began in **2611 BC** and it was completed in 2609 BC. At that time, it was already one of the largest buildings in the world. But that wasn't always the case! For example, the Pyramid of Giza was originally constructed with stones that were too small for use on its own. So, the Egyptians built **another smaller pyramid** on top of it.