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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?

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.

Terminology

Age 14 to 16 Challenge Level:

What do you know about the angles in an equilateral triangle?

What do you know about the angles that meet on a straight line?

What do you know about the angles in an isosceles triangle?

Start by filling in the diagram with the information you know.