Area - triangles, quadrilaterals, compound shapes

What happens to the area and volume of 2D and 3D shapes when you enlarge them?

We usually use squares to measure area, but what if we use triangles instead?

Isometric Areas explored areas of parallelograms in triangular units. Here we explore areas of triangles...

This task challenges you to create symmetrical U shapes out of rods and find their areas.

Start with a triangle. Can you cut it up to make a rectangle?

Can you find the areas of the trapezia in this sequence?

Imagine an infinitely large sheet of square dotty paper on which you can draw triangles of any size you wish (providing each vertex is on a dot). What areas is it/is it not possible to draw?

The points P, Q, R and S are the midpoints of the edges of a non-convex quadrilateral.What do you notice about the quadrilateral PQRS and its area?

A trapezium is divided into four triangles by its diagonals. Can you work out the area of the trapezium?

Prove that a triangle with sides of length 5, 5 and 6 has the same area as a triangle with sides of length 5, 5 and 8. Find other pairs of non-congruent isosceles triangles which have equal areas.