  We show how to define curvature as a measure using the Gauss-Bonnet Theorem
on a family of singular surfaces obtained by gluing together smooth surfaces
along boundary curves. We find an explicit formula for the curvature measure as
a sum of three types of measures: absolutely continuous measures, measures
supported on singular curves, and discrete measures supported on singular
points. We discuss the spectral asymptotics of the Laplacian on these surfaces.
