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Frequently asked questions - Draw

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< Faq | Draw


How do I draw a regular equilateral triangle?

The Drawing toolbar has a button to draw an isosceles triangle but not an equilateral triangle. To draw one, you must do a little geometry. In fact, an equilateral triangle is an isosceles triangle whose height h is:

[math]\displaystyle{ h=\mathit{a.}\sin \left(\frac{\Pi }{3}\right)=\mathit{a.}\sin \left(60\circ \right)=\mathit{a.}\frac{\sqrt{3}}{2}\approx a\times \mathrm{0.866} }[/math] with a representing the length of any edge of the triangle.

To draw an equilateral triangle:

  • click on the triangle to the right of the Basic Shapes icon to open the Basic Shapes toolbar. In the toolbar, click on the Isosceles Triangle button.
  • click and drag to draw a triangle of about the size desired;
  • select the Format ▸ Position and sizemenu;
  • make sure Keep ratio is unchecked;
  • adjust:
    • the height so that it equals the width multiplied by 0.866,
    • the width so that it equals the height divided by 0.866,or
    • both, maintaining the proportion 0.866 between the height and the width;
  • If you change the size of the triangle, click Keep ratio to keep the length of the three sides equal.
  • Click OK.

Another way to create equilateral triangle is to:

  • Draw first edge:
    • Draw a line, holding ⇧ Shift, so it is a straight line.
    • Click on it, press F4 to open properties.
    • Tab Position and Size, set Width to expected length.
    • Click OK.
  • Draw second edge:
    • Copy and paste Ctrl + C, Ctrl + V to create a copy.
    • Press F4 to open properties.
    • Tab Rotation, select Pivot Point on a left position and set Rotation Angle to 60".
  • Draw third edge:
    • Create another copy of the base line with Ctrl + V.
    • Press F4 to open properties.
    • Tab Rotation, select Pivot Point on a right position and set Rotation Angle to 300".
  • Combine edges in one shape:
    • Select all lines.
    • Select menu entry Shape ▸ Combine or ⇧ Shift + Ctrl + K.