Base of Trapezoid Calculator: Find Missing Base (b1 or b2)

Calculate Your Trapezoid's Unknown Base

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Results:

The missing Base (b₁):

Utilize our free online Base of Trapezoid Calculator to effortlessly determine the length of a missing base (b1 or b2) when you're given the trapezoid's area, height, and the other base. This intuitive tool simplifies geometry calculations, providing accurate solutions for any unknown base dimension in seconds.

Formula:

The formula to find a missing base (e.g., b1) of a trapezoid is derived from its area formula:
A = ½ × (b1 + b2) × h
Rearranging for b1:
b1 = (2 × A) / h - b2

Where:

  • A = Area of the trapezoid
  • b1 = First base (the base to be found)
  • b2 = Second base (the known base)
  • h = Height of the trapezoid

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