Coz all 3 angles have to add to 180. If you add 2 90's you get 180 so there are no angles left for the third corner.
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1. Label one of the two unknown angles as "X. Note that one of the three angles in a right triangle is always known, and the size of that angle is 90 degrees. The 90degree angle
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The three angles of a triangle must add up to 180. This would not b...
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One  it is called a right angled triangle. :
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