### At a Glance

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

### Darts and Kites

Explore the geometry of these dart and kite shapes!

### No Right Angle Here

Prove that the internal angle bisectors of a triangle will never be perpendicular to each other.

# Angles in Three Squares

##### Age 11 to 16 Challenge Level:
The picture below shows three squares. Surprisingly, $c = a + b$.
Can you prove it?

Once you've had a chance to think about how to prove it, click to reveal the diagram below.