Question 835723
<pre>
Let the two obtuse angles are &#8736;A and &#8736;B,

Assume they form a linear pair.

1. m&#8736;A + m&#8736;B = 180°   by definition of a linear pair.
2. m&#8736;A > 90°          by definition of "obtuse angle"
3. m&#8736;B > 90°          by definition of "obtuse angle"
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4. m&#8736;A + m&#8736;B > 180°  adding unequals to unequals in the same order gives
                      unequals in the same order.

Statement 4 contradicts statement 1.

Therefore obtuse angles &#8736;A  and &#8736;B cannot form a linear pair.

Edwin</pre>