The first instance of Triangle types was under the 4th grade (U.S.) Math Mission. This exercise practices naming triangles based on their sides using either sides or angles.
Types of Problems
There are two types of problems in this exercise:
- Classify by sides: This problem has a triangle labelled with some of its sides. It asks the user to classify the type of triangle based on this information.
- Classify by angles: This problem has a triangle labelled with some of its angles. It asks users to classify the type of triangle based on this information.
This exercise is easy to get accuracy badges because their are only three possible answers to each problem. The speed badges should still be considered easy, although user will often need to subtract two given angles from 180 to see if the triangle is isosceles or scalene.
- Khan Academy says that an equilateral triangle is isosceles. In other words, the definition of isosceles is a triangle that has at least two congruent sides. Therefore if the triangle is equilateral, user will need to select both isosceles and equilateral.
- Architects use triangles when building bridges, roofs on houses, and other structures.