https://padlet.com/rdownes/planes 7 Constructions to Study The instruments that may be used are: straight-edge: This may be used (together with a pencil) to draw a straight line passing through two marked points. compass: This instrument allows you to draw a circle with a given centre, passing through a given point. It also allows you to take a given segment [AB], and draw a circle centred at a given point C having radius IABI. ruler: This is a straight-edge marked with numbers. It allows you measure the length of segments, and to mark a point B on a given ray with vertex A, such that the length IABI is a given positive number. It can also be employed by sliding it along a set square, or by other methods of sliding, while keeping one or two points on one or two curves. protractor: This allows you to measure angles, and mark points C such that the angle LBAC made with a given ray [AB has a given number of degrees. It can also be employed by sliding it along a line until some line on the protractor lies over a given point. set-squares: You may use these to draw right angles, and angles of 30°, 60°, and 45°. It can also be used by sliding it along a ruler until some coincidence occurs. en-us 2020-07-15 12:40:08 UTC 2022-11-20 12:05:57 UTC hello@padlet.com rdownes https://padlet.com/rdownes/planes/wish/655061580 2020-07-15 12:40:59 UTC https://padlet.com/rdownes/planes/wish/655061580 rdownes https://padlet.com/rdownes/planes/wish/656145233 2020-07-16 15:53:22 UTC https://padlet.com/rdownes/planes/wish/656145233