A 3D shape with all straight edges and flat faces is a polyhedron. Other 3D shapes with least one curved surface are not polyhedra. A 3D shape with regular polygonal faces, meeting at equal angles, is ...
It may be useful to refer to M1 properties of angles; M1 properties of 2D shapes and M5 Polygons if necessary. The sum of the angles inside any polygon can be found by spitting the polygon into ...
A scalene triangle has 3 sides of different lengths and 3 unequal angles. An isosceles triangle has 2 sides of equal length. The dashes on the lines show they are equal in length. The angles at the ...