Classify triangles

Key Notes :

  • An equilateral triangle has 3 equal sides.
  • An isosceles triangle has 2 equal sides.
  • A scalene triangle has 3 different sides.
  • In an acute triangle, all three angles are less than 90°.
  • In a right triangle, one angle is exactly 90°.
  • In an obtuse triangle, one angle is greater than 90°.

Learn with an example

🏫 Is this triangle isosceles?

  • yes
  • no

Look at this triangle :

The triangle is isosceles . 2 sides are the same length.

🏫 Is this triangle equilateral?

  • yes
  • no
  • Look at this triangle:
  • This triangle is not equilateral. 2 angles are the same, but the third angle is different.

🏫 What kind of triangle is this?

  • acute
  • right
  • obtuse
  • This triangle is an obtuse triangle. The 95° angle is greater than 90°.

Let’s practice!🖊️