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Math and Arithmetic

How do you find the area of a object?


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Wiki User
February 15, 2010 10:13PM

a 2D figure you multiply the length by the height. in a 3d object you multiply the length times the width times the height or

  1. Decide what type of shape the object is. This will determine the area formula that you will use.

  2. Step 2

    Find the area of a square or rectangle by multiplying the length times the width. This formula looks like l*w. If the length is 5 and the width is 2, the area is 10 square units.

  3. Step 3

    Calculate the area of a four-sided shape that is not a rectangle by multiplying the base (one of the sides) by the height. The height is a line drawn from the top of the shape to the base forming a right angle with the base. If the base is 10 and the height is 4, the area is 40 square units.

  4. Step 4

    Find the area of a triangle by multiplying the base times the height and then dividing it by two. The base can be any side of the triangle, and the height is the measurement from that base to the vertex above it. This formula looks like (b*h)/2 or ½ b*h and is derived from the fact that a triangle is half of a four-sided shape. If the base is 10 and the height is 4, the area is 20 square units.

  5. Step 5

    Determine the area of a circle by squaring the radius and multiplying it by pi, or 3.14. This formula looks like pi*r^2. If the radius is 5, the area is 78.5 square units.

  6. Step 6

    Find surface area of a three dimensional shape by finding the area of each face separately using the above formulas, and then adding these areas together.