A parallelogram has a base of 10 centimetres, a slanted side of 7 centimetres and a perpendicular height of 6 centimetres. What is its area?

Explication

Area uses the perpendicular height, the straight up and down distance between the two parallel sides, so the calculation is 10 times 6 and the slanted side plays no part. Multiplying by 7 instead measures along a line that leans, which overstates how tall the shape actually stands.