Three identical isosceles triangles are joined together to make a trapezium. Each triangle has base b cm and height h cm. Work out an expression, in terms of b and h for the area of the trapezium.

Formula for the Area of a triangle: A = (base x height)/ 2
Here we have three identical triangles.
Therefore the formula for the Area of the three triangles: A = (b x h) x 3 / 2 = A of trapezium.
Can be simplified as: A = 3/2 x bh = 1.5bh