How do you find the area of the right triangle ABC with A= (-2,7), B= (7,-1), C= (3,9)?

1 Answer
Jun 5, 2015

ABC (with the given coordinates) is not a right triangle.

The area of the triangle can be evaluated by:

  1. Determining the lengths of #|AB|, |BC|, and |AC|#
    #color(white)("XXXX")#Square Root of (#(Delta x)^2 + (Delta y)^2)#)
  2. Determining the perimeter and semi-perimeter
    #color(white)("XXXX")##p =# sum of #|AB| + |BC| + |AC|#
    #color(white)("XXXX")##s= p/2#
  3. Applying Heron's formula
    #color(white)("XXXX")#A= #sqrt(s(s-a)(s-b)(s-c))#

The image below shows the results with the arithmetic details handled by a spreadsheet.

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