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At a Glance

The area of a regular pentagon looks about twice as a big as the pentangle star drawn within it. Is it?

Six Discs

Six circular discs are packed in different-shaped boxes so that the discs touch their neighbours and the sides of the box. Can you put the boxes in order according to the areas of their bases?

Equilateral Areas

ABC and DEF are equilateral triangles of side 3 and 4 respectively. Construct an equilateral triangle whose area is the sum of the area of ABC and DEF.

Of All the Areas

Age 14 to 16
Challenge Level

You may find it useful to take a look at More Isometric Areas.
These diagrams might help you to work out the areas of the tilted triangles. 

The top diagrams show how drawing a non-tilted triangle around the tilted triangle could help you to find the area of the tilted triangle.

Area of tilted triangle = Area of blue triangle - Area of 3 green triangles

This diagram show some lines that can be drawn inside the tilted triangle:

Area of tilted triangle = Area of pink triangle + Area of 3 blue triangles