2. Pyramids Lesson 11-3

3. History When we think of pyramids we think of the Great Pyramids of Egypt. They are actually Square Pyramids, because their base is a Square.

4. Pyramids in Egypt The Great Pyramid of Khufu, at Giza, Egypt, is 751 feet long on each side at the base, is 450 feet high, and is composed of approximately 2 million blocks of stone, each weighing more than 2 tons. The maximum error between side lengths is less than 0.1%. The sloping angle of its sides is 51°51'. Each side is oriented with the compass points of north, south, east, and west. Each cross section of the pyramid (parallel to the base) is a square. Until the 19th century, the Great Pyramid at Giza was the tallest building in the world. At over 4500 years in age, it is the only one of the famous Seven Wonders of the Ancient World that remains standing. According to the Greek historian Herodotus, the Great Pyramid was built as a tomb for the Pharaoh Khufu.

5. Parts of a Pyramid To find slant height, remember to use Pythagorean Theorem

6. Finding Slant Height Example

7. Surface Area of a Square Pyramid

8. Calculate surface area of a square pyramid Example Surfaces: 4 triangles 1 square Calculate area of a triangle: Multiply by 4: 4(20.4)=81.6 sq. units Calculate area of a square: Total surface area=81.6 + 16 =97.6 sq. units

9. Volume of a pyramid A pyramid is a solid with a polygonal base and several triangular lateral faces.. The lateral faces meet at a common vertex. The height of the pyramid is the perpendicular distance from the base to the vertex.

10. Calculate the Volume of a Pyramid

11. You try!! A regular pyramid is shown at the left. Find the volume of the pyramid to the nearest cubic unit. Choose: 800 267 80 27