Constructions

Tools Required COMPASS STRAIGHTEDGE or Ruler

Copy a Segment Use compass to measure 𝐴𝐵 Place compass at point 𝐶 and draw an arc Label points on arc 𝐷, 𝐸, 𝐹, … Use straight edge to draw 𝐶𝐷 , 𝐶𝐸 , 𝐶𝐹 , …

Bisect an Angle Place compass at point 𝐴 and draw arc through both sides of ∠𝐶𝐴𝐵 Label new points on sides of the angle 𝐷 and 𝐸 Place compass at point 𝐷 and draw an arc in the interior of ∠𝐶𝐴𝐵 Without adjusting the compass do the same at point 𝐸 to create point 𝐹 Use straightedge to draw 𝐴𝐹

Try Bisecting an Obtuse Angle Use protractor to measure angles to check your bisection 𝑚 ∠𝐶𝐴𝐵 = 𝑚 ∠𝐶𝐴𝐹 = 𝑚 ∠𝐵𝐴𝐹 =

Try Bisecting a Straight Angle Use protractor to measure angles to check your bisection 𝑚 ∠𝐶𝐴𝐵 = 𝑚 ∠𝐶𝐴𝐹 = 𝑚 ∠𝐵𝐴𝐹 =

Perpendicular through a Point on the Line Place compass at point 𝐴 and create points 𝐶 and 𝐵 on line 𝑛 such that 𝐴𝐶 ≅ 𝐴𝐵 Adjust compass and place at point 𝐶, then draw an arc above or below point 𝐴 Without adjusting the compass do the same at point 𝐵 to create point 𝐷 Use straightedge to draw 𝐴𝐷

Perpendicular Bisector and Midpoint Open compass greater than 1 2 𝐶𝐵 Place compass at point 𝐶 and draw arcs above and below the segment Without adjusting compass place at point 𝐵 and draw arcs creating points 𝐷 and 𝐸 Use straightedge to draw 𝐷𝐸 while creating point 𝑀 on 𝐶𝐵

Perpendicular through a Point not on the Line Place compass at point 𝐹 to create points 𝐴 and 𝐵 on line 𝑛 such that Place compass at point 𝐴 and draw an arc below line 𝑛 Without adjusting the compass place at point 𝐵 to draw an arc below line 𝑛 to create point 𝐶 Use straightedge to draw 𝐶𝐹

Copy an Angle Place compass at point 𝐵 and draw an arc through both sides of ∠𝐴𝐵𝐶 creating points 𝐹 and 𝐺 Without adjusting compass place at point 𝐷 and draw the “same” arc creating point 𝐻 Use compass to copy 𝐹𝐺 at point 𝐻 creating point 𝐼 Use straightedge to draw 𝐷𝐼

Try constructing the Perpendicular bisector of each side