Video Transcript
Which of the following shapes has rotational symmetry? Kite, square, trapezoid, scalene triangle, isosceles triangle.
To solve this question, we’ll need to sketch each of these shapes. We have a kite, a square, a trapezoid, a scalene triangle — remember this is a triangle where all three sides are a different length — and the last one isosceles triangle. Rotational symmetry is when an object is rotated or turned around the centre point.
Now, we’ll need to give each of these shapes a centre point. Let’s rotate each of these shapes 90 degrees to the right and see what happens. For an object to have rotational symmetry, the objects that’s rotated or turned around a centre point must appear the same after we’ve rotated them.
When you rotate a figure around a centre point and it appears the same as before you rotated it, we say that that object has rotational symmetry. Only one of these objects has rotational symmetry. And that object is the square. The square appears the same after it’s been rotated around a central point.
We can say that a square has rotational symmetry.
