Have you ever looked at a gold bar and wondered how much space it is taking up? To find its volume, you need to multiply its cross-sectional area by its height. The cross-section of a gold bar is that of a trapezium.
A trapezium is a quadrilateral that has 2 sides that are parallel to each other. One side of the parallel line is typically longer than the other when both are of the same length; we normally refer to it as a rectangle instead. There are many different types of trapezoids. A right trapezoid has two adjacent right angles. An acute trapezoid has two closest acute angles on its longer bottom edge, whereas an obtuse trapezoid has one acute and one obtuse angle on every bottom. An isosceles trapezoid is a trapezoid where the sides have the same length, and the base angles have the same measure.
To measure the area of a trapezium, we need to know the length of the two parallel sides of the trapezium and the distance (right angle/shortest), also known as the height of a trapezium. The area is the product between the sum of the length of the two parallel sides and the height.
Now, with this knowledge, you can find the volume of a gold bar without having to drop your precious gold bar into a measuring cylinder and get it wet.