Geometric shapes

Basic 2D Shapes

Many words for geometric (géométrique) shapes are very similar to their English counterparts, such as le cercle (the circle), le triangle (the triangle), and le rectangle (the rectangle).

The circle is a very simple geometric shape.
Le cercle est une forme géométrique très simple.
Certain geometric shapes are triangles.
Certaines formes géométriques sont des triangles.

When discussing polygons, you'll also use the word l'angle (the angle, m).

A rectangle has four angles.
Un rectangle a quatre angles.
The teacher explains the angles of the triangle.
Le professeur explique les angles du triangle.

3D Shapes and Objects

When objects have volume, you'll use words for 3D forms like la sphère (the sphere), le cube (the cube), and le cylindre (the cylinder).

Pay attention to their genders: sphère is feminine, while cube and cylindre are masculine.

The ball is a sphere, not a circle.
La balle est une sphère, pas un cercle.
Certain modern buildings are cubes or cylinders.
Certains bâtiments modernes sont des cubes ou des cylindres.
The child is playing with a red cube.
L'enfant joue avec un cube rouge.