Any regular polygon with more than 4 sides.
Polygons with more than 4 sides don't have to be regular to have all obtuse angles. The number of degrees in an average angle of an n-sided polygon will be
(n-2)*180/n
That number will be greater than 90 degrees when
(n-2)*180/n > 90
180n - 360 > 90n (multiply by n)
90n > 360 (add 360-90n)
n > 4 (divide by 90)
Any polygon with 5 or more sides can be drawn so that it has all obtuse angles.
Many 3-dimensional shapes have all obtuse angles, a dodecahedron for example.
Polygons with more than 4 sides don't have to be regular to have all obtuse angles. The number of degrees in an average angle of an n-sided polygon will be
(n-2)*180/n
That number will be greater than 90 degrees when
(n-2)*180/n > 90
180n - 360 > 90n (multiply by n)
90n > 360 (add 360-90n)
n > 4 (divide by 90)
Any polygon with 5 or more sides can be drawn so that it has all obtuse angles.
Many 3-dimensional shapes have all obtuse angles, a dodecahedron for example.