These straight lines form a family and the curves that you see, called envelopes, are tangent to each line in the family.
Draw two base lines and mark the same number of points at equal distances along each line. Join the outermost point on one base […]
Describe the different symmetries. Draw the picture yourself. Draw your own designs using this idea. Can you explain how this 2-dimensional picture appears to show a 3-dimensional object?
You could use paperclip […]
Copy the picture to draw this spiral. Then create your own elephant. The numbers in the centres of the squares give the radii of the quarter circles that you need to draw.
What do you notice about this sequence of numbers 1, 1, 2, 3, 5, 8, 13, 21 … ? […]
1a) Double click on the picture above to start the movie showing how to draw a circle using the paperclip compass.
1b) Draw 2 circles of the same radius with centres A and B so that each circle goes through the centre of the other […]
a. Draw 2 circles with equal radii, intersecting at C, so that each goes through the centre of the other.
b. Draw a third circle of the same radius with centre C.
c. Draw 4 more circles with centres on the circle centre A and passing through A.
Accurately copy the following patterns and vary them to make your own designs.
Draw two base lines and mark the same number of points at equal distances along each line. Join […]
Draw a circle and mark 24 points equally spaced around the circumference. To do this, draw a circle and mark the centre, and mark your first point on […]
Cardioid technology is used in microphones and speakers. Cardioids appear in the motion of planets and in many other ways. See this YouTube video.
To draw a cardioid, first draw a circle, then carefully mark 36 points around the circle at 10 degree intervals and number the points n = 0 […]
b) Choose a small distance d, mark this distance along the edge of the rectangle and draw a straight line from one vertex of the rectangle to this point as in Step 1.
c) Mark the distance d along the next edge and […]
If you have geometry instruments then try it for yourself. What do you notice?
Can you give reasons for your answer to the question “Is it possible?”
Click here for The Notes for Teachers. […]