Area and volume in non-Euclidean geometry

We give an overview old and recent results on areas and volumes in hyperbolic
and spherical geometries. First, we observe the known results about Heron’s and Ptolemy’s theorems. Then we present non-Euclidean analogues of the Brahmagupta’s theorem for a cyclic quadrilateral. We produce also hyperbolic and spherical versions of the Bretschneider’s formula for the area of a quadrilateral. We give hyperbolic and spherical analogues of the Casey’s theorem which is a generalization of the Ptolemy’s equation. We give a short historical review of volume calculations for non-Euclidean polyhedra. Then we concentrate
on recent results concerning Seidel’s problem on the volume of an ideal tetrahedron, Sforza’s formula for a compact tetrahedron in H3 or S3 and volumes of non-Euclidean octahedra with symmetries