For the area of a parallelogram, you must use the formula : base x height
First you figure the height of the shape, and then only multiply that by the base, giving you the area.
For the perimeter, you could find the height, and use pythagoras' theorem to help you find the missing lengths if there are any, and add all sides up.
For the area of a triangle, you must use the formula : (Base x Height) / 2
Simply just by dividing the base by two and multiplying that by the height, of which you could also find with Pythagoras' Theorem if it isn't shown, or just multiply both height and base and diving the product by two.
For the perimeter, use pythagoras' theorem if needed: a^2 + b^2 = c^2
Add all sides up