An isosceles triangle, isosceles trapezium.
More generally, any polygon where the side to the left of the bottom is the same as the side to the right of the bottom, and the next pair of sides are the same as one another (but different from the first pair), and so on. So that is an infinite number added to the "only one".
A truncated parabola.
An ellipse.
and there are loads more.
A symmetrical shape is said to have line symmetry. A shape that has line symmetry can have one or more lines of symmetry
An isosceles triangle has one line of symmetry
triangle
a triangle only has one line of symmetry
No.
a shape with a line of symmetry
A symmetrical shape is said to have line symmetry. A shape that has line symmetry can have one or more lines of symmetry
The 2D shape which has one line of symmetry is the trapezium.
An isosceles triangle has one line of symmetry
An isosceles triangle has one line of symmetry
How about an isosceles triangle which has one line of symmetry
square
a leaf
An isosceles triangle and a kite have only one line of symmetry.
A kite has one line of symmetry.
triangle
a triangle only has one line of symmetry