A projector according to the present disclosure includes: a projection unit, a lens unit, an imaging unit, and a computing unit. The projection unit displays a first image. The lens unit projects the first image that is displayed by the projection unit. The imaging unit images a second image, which is projected by another projector, through the lens unit. The computing unit computes a distance between a surface on which the second image is projected and the another projector. Such the distance is computed from imaging data of the second image imaged by the imaging unit, and from spacing information on a spacing between the projector concerned and the another projector.