Work out parallelogram area instantly with clear inputs, formula shown and shareable results.
A parallelogram has the same area as a rectangle on the same base with the same perpendicular height, so A = base × height. The slant side and height give the interior angle through sin θ = h / side.
Area
A = base × perpendicular height
Interior angle
θ = arcsin(height ÷ slant side)
That would give the area only for a rectangle. For a slanted parallelogram you need the perpendicular height, which is shorter than the slant side.
Yes, and adjacent angles are supplementary, which is why the two reported angles add to 180°.