How do you find the height of a trapezoid?

How Do I Find the Unknown Height of a Trapezoid?

• Answer:

  Finding the unknown height of the a trapezoid is a common mathematical problem encountered in geometry. For those unfamiliar with the process of calculating the unknown height, however, the process may seem quite daunting. In fact, given the area and base lengths of the trapezoid, calculating the unknown measure of the height is a simple calculation that anyone can compute in a few minutes of work. Difficulty: Moderately Easy Instructions Write out the equation to find the area of a trapezoid. In this case "Area=height(b1+b2) / (2). Given the height and the two base lengths, b1 and b2, you can re-arrange the equation to determine the height. Re-arrange the equation to solve for height. When done properly, the new equation becomes "Height=2Area/(b1+b2). Enter the known values into the equation and solve. For example, If the area is 30 and b1 is 4 and b2 is 8, then the equation can be written as "Height=2 x 30/(4+8). Multiply 2 by 30 and you get 60. Add 4 and 8 to get 12. Divide 60 by 12 to solve for the height. In this example, the height is 5.