which of the following have rotation symmetry?

Question

-square -rectangle -right triangle -rhombus -equilateral triangle

Answer 1

square. rectangle, equilateral triangle, rhombus
see http://www.learner.org/channel/courses/learningmath/geometry/session7/part_b/index.html

Answer 2

All but the right triangle necessarily have rotational symmetry in the plane. A right triangle MIGHT also - in 3D a 45-90-45 can be rotated out of the plane about an axis perpendicullar to the hypotenuse and intersecting the vertex of the 90 angle.
(I assume that we are ignoring those things which when rotated through 360 degrees are indistinguishable from the original - this is usually regarded as a trivial case, but not all things have this property!) Anyway, we have to be careful about defining the number of dimensions of the space we want to talk about. But these are more advanced considerations.

Answer 3

A square has rotational symmetry every 90 degrees
A rectangle has it every 180 degrees
A right triangle does not have rotational symmetry
The rhombus has 180-degree symmetry
Equilateral triangle has 120-degree symmetry

Answer 4

I'm confused
you can find rotation sym for all of these
the trick is finding the line of rotation
But if you were to pick one that doesn't readily have one it would be the right triangle

Answer 5

square, and equilateral triangle,, no matter how you rotate them they are the same on all sides...

Answer 6

I am pretty sure it is a square

(not sure)