a triangle on top of a square
No, the sun is not a plane figure. It is a 3-dimentional astronomical object we call a star. Plane figures have just two dimensions.
A seven sided figure.
A circle perhaps
A flat shape.
cone that is my answer
probably a sphere
Party hats!
Parallelepipedal, approximatively
Lotus
A four-sided plane figure with four right angles
Wouldn't you like to know...
a plane