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Question
What universal set (s) would you propose for the following:
The set of right triangles.
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Solution 1
For the set of right triangles, the universal set can be the set of triangles or the set of polygons.
Solution 2
Right triangle is a type of triangle. So the set of triangles contain all types of triangles.
∴ U = {x : x is a triangle in a plane)
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