math

The base of a regular pyramid is a square whose sides have a length 8 cm. If a lateral edge of this pyramid has length 20 cm, what is the surface area of the pyramid?

  1. 👍
  2. 👎
  3. 👁
  1. Look at one of the triangles, which is isosceles with a base of 8 and each of the equal sides of length 20

    Height of triangle: let it be h
    h^2 + 4^2 = 20^2
    h^2 = 384
    h = √384

    Area of one triangle = (1/2)(8)(√384) = 4√384
    Assuming the surface area consists only of the 4 triangles,
    surface area = 4(4√384) or 16(8√6) = 128√6

    1. 👍
    2. 👎
  2. Thanks, but I need the base too - that I can do by myself!

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Math

    the great pyramid of cheops is a square based pyramid with a height of 147 meters and a base length of 230 meters. find the angle to the nearest degree that one of the edges of the pyramid makes with the base

  2. math

    A regular hexagonal pyramid whose base perimeter is 60cm has an altitude of 30cm. The volume of the pyramid is??

  3. Math

    The base of a pyramid-shaped tank is a square with sides of length 12 feet, and the vertex of the pyramid is 10 feet above the base. The tank is filled to a depth of 4 feet, and water is flowing into the tank at the rate of 2

  4. Maths

    The height and volume of a square based pyramid are 12 cm and 100cm respectively.Find the length of the square base?

  1. geometry

    Find the volume of a pyramid with a square base, where the side length of the base is 18.5 in and the height of the pyramid is 10.9. Round your answer to the nearest tenth of a cubic inch.

  2. Geometry

    The Great Pyramid of Cheops is a right square pyramid with height of 148 m and a square base with a perimeter of 940 m. The Transamerica Building in San Francisco has the basic shape of a right square pyramid that has a square

  3. Maths

    OPQRS is a right pyramid whose base is a square of sides 12cm each. Given that the slant height of the pyramid is 15cm. Find the height of the pyramid. The volume of the pyramid and the total surface of the pyramid.

  4. Mathematics

    OPQRS is a right pyramid whose base is a square of sides 12cm each. Given that the slant height of the pyramid is 15cm. Find the height of the pyramid, the volume of the pyramid, and the total surface area of the pyramid by first

  1. Math

    Ira built a model of the great pyramid in Egypt for a school project. The great pyramid had a square base with sides of length 756feet the height of the great pyramid is 481 feet Ira made his model pyramid using a scale of 1 inch

  2. Geometry please help me need to finish!

    The slant height of a regular pentagonal pyramid is 6 cm, and the length of each side of the base is 3 cm. Find the lateral area.

  3. MATH! PLEASE REPLY ASAP!

    OPQRS is a regular square-pyramid whose base has sides of 7 cm. Given that the total surface area of the pyramid is 161 cm2, find its slant height.

  4. Math

    A right pyramid has a square base of sides 10cm each and a slant height of 15cm . Draw a net of the pyramid and label its dimensions

You can view more similar questions or ask a new question.