The answer is a septahedron, 11 letter answer
triangular prism
A quadrilateral is a shape that has four sides and has 13 letters in its name.
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An 11 sided shape is an Eptogon
Tetrahedron
semicircles
a bottomhead
The answer is a septahedron, 11 letter answer
a symmetrical shape
triangular prism
a bottomhead
Ss
I cannot think of any 2-d shape. The 3-d shape with four faces is a tetrahedron.
Septahedron
a isosceles triangle has at least 1 line of symmetry but only has 9 letters
There are a great many of them. One nice one is the icosahedron, which has 20 vertices and 11 letters.