There is no reason because the statement for which you are seeking a reason is patently FALSE. Consider a pentagram, for example.
True
The statement is no true.
No. Only 2 altitudes can intersect at a point. * * * * * True but even they do not meet in the interior. The altitudes of a right angles triangle meet at the right angled vertex. The vertex is at the boundary of the triangle, not in the interior.
72 degrees unless you are making a pentagon then you would cut the boards at 1/2 of 72 degrees or 36 degrees. the secret is to remember there are 360 degrees in total. just divide that by whatever equal sided shape you need.
It is true only when the parallelogram is in the form of a rhombus, and thus the two diagonals are perpendicular to each other.
True
The statement is no true.
No. Only 2 altitudes can intersect at a point. * * * * * True but even they do not meet in the interior. The altitudes of a right angles triangle meet at the right angled vertex. The vertex is at the boundary of the triangle, not in the interior.
They are of equal length.
72 degrees unless you are making a pentagon then you would cut the boards at 1/2 of 72 degrees or 36 degrees. the secret is to remember there are 360 degrees in total. just divide that by whatever equal sided shape you need.
TRUE!
Yes.
The 2 diagonals in an isosceles trapezoid are of equal lengths
false they intersect at a single point
True
Yes, they can be. Here is an example to see how this is true. Construct two perpendicular lines AB and CD that intersect at a point O. Let AO = CO, BO = DO and AO ≠ BO, then ABDC forms an isosceles trapezoid. If the lines are not perpendicular, then also ABDC is an isosceles trapezoid and it has perpendicular diagonals.
It is true only when the parallelogram is in the form of a rhombus, and thus the two diagonals are perpendicular to each other.