Idéllo Elo’s Missions - Go to homepage.

Oops! You must be signed in with your IDÉLLO account to access the Mission.

Sign in

The Properties of Triangles

  • Grade 5
  • Mathematics
  • Spatial Sense


In this mission, students explore the properties of triangles. Students recognize that they can be classified by angle or side measurements and draw appropriate conclusions. In addition, students describe triangles according to their properties by observing constellations.

Learning goals

  • I identify the geometric properties of triangles.
  • I describe a triangle according to the measurements of its sides and angles.


  • acute
  • acutangle
  • obtuse
  • obtusangle
  • equilateral
  • scalene
  • isosceles
  • congruent