A convex polygon is one in which each interior angle measures less than 180.
Let’s first find the measure of each interior angle in a regular 11-gon.
It is equal to (9 * 180) ÷ 11 = 147.27.
Therefore, all angles in a convex, 11-gon may be obtuse (more than 90)
like in a regular 11-gon.
Figure shows the 11-gon with all obtuse angles.