Constructing Triangles

Constructing SSS Triangles

Constructing SSS Triangles

What are SSS Triangle constructions?

• SSS just stands for side, side, side!

• An SSS triangle construction is a triangle drawn accurately if you are told the lengths of its three sides and no other information

• You will need:

  • a pencil

  • a ruler

  • a pair of compasses

How do I construct an SSS triangle?

• STEP 1
  Use a ruler to draw the longest side as the horizontal base near the bottom of the space you have been given

  • This needs to be accurate

  • Write its length (with units) just underneath

• STEP 2
  Open your compasses so that the length from the compass point to the tip of your pencil is exactly the length of one of the remaining sides

  • Being extra careful not to change the length, put the compass point on one end of the horizontal line you have drawn and draw an arc above the horizontal line

  • You can draw a full circle rather than an arc if you prefer

• STEP 3
  Open your compasses so that the length from the compass point to the tip of your pencil is exactly the length of the third side

  • Being extra careful not to change the length, put the compass point on the other end of the horizontal line and draw another arc, making sure that it crosses the first arc

• STEP 4

  Use your ruler to draw straight lines from each end of the horizontal line to the point where the arcs cross

• STEP 5
  Use your ruler to check that the two new lines are exactly equal to the lengths given in the question

  • When you are confident that they are accurate, label the lines with their lengths and units

• Do not rub out your arcs as the examiner will use these to check your work

• Sometimes the instructions will include a triangle name such as triangle ABC

  • Make sure you label each vertex with the correct letters