which shape does not have a rotational symmetry?
trapezoid, regular pentagon, circle, or square
2007-11-28 09:13:56 · 14 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Think about it -- which shape is not symmetric?
2007-11-28 09:16:35 · answer #1 · answered by rkeech 5 · 1⤊ 0⤋
First off, let's review what rotational symmetry is. Rotational symmetry is when you can rotate the object by n degrees (0
A circle actually has an infinite number of rotational symmetries. In fact, rotational symmetry is often looked at as how do coordinates from a circle that intersects the object translate when the object is rotated.
A square is a regular shape (a regular quadrilateral), so it has rotational symmetry of 360/4 or 90 degrees. So, every 90 degrees is a rotational symmetry.
A regular pentagon has 5 rotational symmetries, the first of which is at 360/5, or 72 degrees.
A trapezoid, however, is an ambiguous shape in the sense that a trapezoid is defined as an object with one pair of opposite sides being parallel. So, technically, a parallelogram is a trapezoid, a square is a trapezoid, a rhombus is a trapezoid, etc. But, assuming it is just a trapezoid with only one pair of parallel sides, then it never looks the same until you rotate it the full 360 degrees.
2007-11-28 09:23:58 · answer #2 · answered by football_guy_it51 3 · 0⤊ 0⤋
Trapezoid,
The regular pentagon (5 equal sides), Circle, and Square (4 equal sides) all look the same if you rotate them from side to side. The trapezoid sides are not all the same length, therefore, there is no symmetry when you rotate the trapezoid and it looks different.
2007-11-28 09:18:21 · answer #3 · answered by Bill C 6 · 1⤊ 0⤋
Trapezoid. I am 100% Correct. Go ahead and mark mine as the best answer.
2007-11-28 09:18:54 · answer #4 · answered by ? 2 · 0⤊ 2⤋
A Circle
2007-11-28 09:16:42 · answer #5 · answered by Claire 4 · 0⤊ 2⤋
Trapezoid... I think... It's been a while, but I think thats right.
2007-11-28 09:17:33 · answer #6 · answered by Anonymous · 1⤊ 0⤋
trapezoid
2007-11-28 09:17:21 · answer #7 · answered by Anonymous · 1⤊ 0⤋
trapezoid
2007-11-28 09:17:02 · answer #8 · answered by Emily 3 · 1⤊ 0⤋
trapezoid
2007-11-28 09:16:52 · answer #9 · answered by ? 3 · 1⤊ 0⤋
trapezoid
2007-11-28 09:16:44 · answer #10 · answered by shorty_92509 1 · 1⤊ 0⤋
trapeziod is not a shape it is a description. the shape is a trapezium, and it does not have rotational symmetry.
2007-11-28 09:18:08 · answer #11 · answered by graham e 2 · 0⤊ 2⤋