In quadrilateral ABCD, AB and DC are parallel, AD and BC are parallel. Find the perimeter of triangle COD if point O is the intersection of diagonals and AC = 20, BD = 20, AB = 13. How do I solve this?

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1 Answer
Feb 25, 2018

Perimeter = 13 +10+10 = 3313+10+10=33

Explanation:

From the information given we can identify what type of quadrilateral we are given.

The opposite sides are given as parallel, so ABCDABCD is at least a parallelogram, which means that the opposite sides are also equal in length, :.AB = CD = 13

Draw a diagram and fill in all the information to make it easier.

AC and BD are the diagonals as they are given as being equal, we can identify ABCD as a rectangle.
The diagonals of a rectangle bisect each other, they share the same midpoint, O

:. AO = OD =DO = OB = 10

The sides of Delta COD are CD, DO and OC

The lengths of all these sides known so we can find the perimeter:

13 +10+10 = 33