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From the solution to the problem Strange Rectangle (November 2001) you know angles SPQ and SRQ are right angles, angle PQR is 45 degrees and angle PSQ is 135 degrees.
For the first part you need to know
\tan 60^{\circ} = \sqrt3
When you take x=\sqrt 3 and y=1 and use the triangles in the diagram you can find the exact values of the sine, cosine and tangent of these angles in surd form.
Look carefully at AS and SD for the second part. Here you take x=\sqrt 2 + 1 and y=1 to find the exact values of the trigonometric ratios for 22.5 degrees and 67.5 degrees.
A triangle PQR, right angled at P, slides on a horizontal floor with Q and R in contact with perpendicular walls. What is the locus of P?
Four rods are hinged at their ends to form a quadrilateral. How can you maximise its area?
ABCD is a rectangle and P, Q, R and S are moveable points on the edges dividing the edges in certain ratios. Strangely PQRS is always a cyclic quadrilateral and you can find the angles.