







A schedule for observing our peers 
20150123 

From Jennifer: I am a sales trainer. Each month we need to observe one of our peers and give feedback. What this means is every month, not only am I observing someone, but someone is also observing me. For example, in January, Amy observes Tracy, Tracy observes Rachel, Rachel observes Ryan, and so on. The last person would then observe Amy, bringing it full circle. There are 10 trainers on my team. How do I set it up to where each trainer observes another trainer only once over the course of the year (and in return, each trainer is only being observed once by each person)? I know they will eventually repeat but would that start in the 10th month? Answered by Robert Dawson. 





A rotation schedule for 14 teams 
20140708 

From Daniel: I am organizing team activities for a summer camp. We have 14 teams and 7 rotations and 7 different games. every team will play a different game each rotation. Where I am having trouble is I would like each team to play a different team each rotation without a repeat. Is that possible? if so what is the formula? Answered by Victoria West. 





Symmetries of a polyhedron 
20090302 

From Vincent: I want to ask is there a formula to find out the number of axes of rotation & plane
of reflection of a 3D figure, like pentagon, pyramid? Answered by Chris Fisher. 





Rotating letters 
20071126 

From sherry: Ms. Thomas said to her class, when my older was little his nickname was Zed. The nickname my brother gave me was like his but with the first letter turned 90 degrees the second letter changed to the first letter of the alphabet and the third letter turned a half rotation. Does anyone know what my nickname was. My brother gave me the nickname because I slept too much. Could you please explain this to me so I can help my child solve it. Thanks Answered by Leeanne Boehm. 





Rotational energy needs 
20070829 

From will: how much energy in KW do i need to start and subsequently rotate a 4 ton fly wheel of 1 metre radius at 12 rpm? Answered by Stephen La Rocque. 





Three points on the circumference of a circle 
20070730 

From Bharathi: given a circle with radius r and a point x,y on its circumference,output two other
points x1,y1 and x2,y2 on the circle so thar all 3 points form a equilateral triangle. Answered by Stephen La Rocque. 





A rotated rectangle 
20070416 

From Graham: There is a circle inside which from the centre to the top is a rectangle. Size is unimportant.
If I the rectangle is at 0 degrees and I know the coordinates of the 4 corners I can do a check to see
whether a given point x,y is inside the rectangle or not.
Question : If the rectangle is rotated by 50 degrees how do I check then as the lines of the rectangle are not
perfectly straight with regards to x and y ie at 0 degrees x changes but y is constant and vice versa.
At 50 degrees x and y change together. Answered by Penny Nom. 





The product of of two rotations 
20061217 

From Katie: Is the product of of two rotations over a different center point always a translation? Answered by Walter Whiteley. 





Two gears 
20041014 

From Lindsay: "There are two gears, a small one on the left and a larger one on the right. The gear on the right makes 1 revolution. The gear on the left makes two revolutions. Suppose the gear on the right is turned through an obtuse angle. Will the gear on the left make a full turn?" Answered by Penny Nom. 





Lines of symmetry 
20020422 

From Cindie: How many lines of symmetry do the following figures contain? trapezoid: rhombus: hexagon: pentagon: Answered by Walter Whiteley. 





Rotation 
20010125 

From A student: If I have a rectangle 2inches long and 4 inches wide and I rotate the rectangle 45 degrees will the length still be 2 inches? Answered by Penny Nom. 





The angle of rotation 
20000803 

From Jay: I have the following information Given. (X1, Y1) Origional Point (X2, Y2) Origional Point After a Rotation (Xa, Xb) Center of Rotation What formula would I use to figure out the angle the point was rotated? Answered by Chris Fisher and Harley Weston. 





Rolling Circles 
19990912 

From Craig Ellis: We have a circle of radius 3. inside the circle and tangent to the circle of radius 3 at one point is a circleof radius 1. The question is if we could roll the smaller circle around the inside of the larger circle how many revolutions would it take to get around to where we started. Answered by Chris Fisher and Walter Whiteley. 





Shapepreserving transformations 
19990504 

From J McAndrew: A shape preserves its shape if a rotation, translation or scaling is performed on it. Are these the only continuous transformations which have this property? These transformations if performed on the parts and then summed have the same effect as the transformation being applied to the whole; are these linear transformations? Who, and what area of mathematics has classified all transformations of this type completely? Answered by Chris Fisher. 





Frieze Patterns 
19980819 

From Brian Bairstow: I am doing a research project on frieze patterns (also called band patterns or border patterns). I know that there are exactly seven different types of frieze patterns, but I have been unable to find a proof for this. If you could tell me this proof, or tell me some internet sites on which I can find material on this, I would be very grateful. Answered by Chris Fisher. 





l'équation d'une rotation dans un graphique cartésien 
20011114 

From Ghaith: je d6sir que vous me rafraichissez un peu la mémoire s.v.p. j'aimerai savoir l'équation d'une rotation dans un graphique cartésien merci Answered by Claude Tardif. 

