Any polygonal shape, other than a triangle can have perpendicular lines.
a triangle * * * * * Wrong on at least two counts: A triangle need not be irregular and a triangle is not a three dimensional shape. Any pyramid other than a regular triangular pyramid (tetrahedron), any prism other than a cube are some examples.
Any geometric shape that has more than three sides.
Any shape, other than a triangle can have a pair of perpendicular sides.
equilateral triangle
Triangle means 3 angles. No other shape exists and any three angle shape is a triangle
Any polygonal shape, other than a triangle can have perpendicular lines.
a triangle * * * * * Wrong on at least two counts: A triangle need not be irregular and a triangle is not a three dimensional shape. Any pyramid other than a regular triangular pyramid (tetrahedron), any prism other than a cube are some examples.
Any geometric shape that has more than three sides.
Any polygon, other than a triangle, can have 2 parallel sides.
There is no shape that is made up 3 sides that is not a triangle. Any shape that is made up of 3 sides is classified as a triangle no matter what shape or size it is.
Any shape that is enclosed and has three sides is a triangle.
Any polygon, other than a triangle, can have a pair (or more) of parallel lines.
Any shape, other than a triangle can have a pair of perpendicular sides.
equilateral triangle
It could be any irregular polygon other than a triangle.
Any closed shape can have angles greater than 90 degrees. A triangle doesn't need to have any, but it can have one of them if it wants to. A shape with four sides doesn't need to have any, but it can have 2 or 3 of them if it wants to. Shapes with more than 4 sides must have some.