Doesn't what violate the law of the excluded middle? You asked a question — how can a question violate anything? Some answers might, but you need to ask about a specific such answer. “As the negation could be a scalene, obtuse, or equilateral triangle, etc. read more
An equilateral triangle is a subset of an isosceles triangle and so is still in the isosceles set because two of its sides are equal. An obtuse triangle refers to one of the angles being greater than 90 degrees and so this can still be an isosceles triangle. The negation of an isosceles can only be scalene triangles. read more
An isosceles triangle is a trianglewith (at least) two equal sides. the two equal sides have length and the remaining side has length . This property is equivalent to two angles of the triangle being equal. An isosceles triangle therefore has both two equal sides and two equal angles. read more
An isosceles triangle is a triangle with two sides of the same length. These two equal sides always join at the same angle to the base (the third side), and meet directly above the midpoint of the base. read more