Last modified on 25 January 2011, at 18:50

Trigonometry/Exercise: Congruent Triangles

Congruencies-UnLabelled.svg

In The diagram above, how many triangles are there?
Count The Triangles (With Labels)
  • Label the vertices as shown in the diagram on the right.
  • Now list the triangles using the letters at the corners, for example \triangle ADE is a triangle. The symbol '\triangle' before the \displaystyle ADE is just read as 'triangle'. You should put the symbol before the triangles you list, so your list might start:
\displaystyle \triangle ACE, \triangle ADE,
  • Now, which of the triangles you have listed are congruent to each other?
  • Which of the triangles you have listed are similar to each other but are not congruent?
  • Do any of the triangles have an obtuse angle (an angle greater than 90 degrees)?