An equilateral triangle is sitting on top of a square.
What is the radius of the circle that circumscribes this shape?
A circle has centre O and angle POR = angle QOR. Construct tangents
at P and Q meeting at T. Draw a circle with diameter OT. Do P and Q
lie inside, or on, or outside this circle?
It is impossible to trisect an angle using only ruler and compasses
but it can be done using a carpenter's square.
Triangle ABC has a right angle at C. ACRS and CBPQ are squares.
ST and PU are perpendicular to AB produced.
Show that ST + PU = AB