Always, Sometimes or Never

1. Always, Sometimes or Never Classify each of the following scenarios as always sometimes or never

2. Isosceles triangles are obtuse triangles. Solution: We can write this as, “If a triangle is isosceles, then it is obtuse. Can we draw an example of an isosceles triangle that is also obtuse? Sure! We just need to create one angle bigger than 90 , after all. On the other hand we know that just because a triangle is isosceles doesn’t mean it has to be obtuse; we’ve seen acute isosceles triangles. So the answer will be sometimes.

3. Always, Sometimes or Never Isosceles triangle are acute triangles. Isosceles triangles are equilateral Equilateral triangles are scalene. Scalene triangles are isosceles. Isosceles triangles are right triangles. A triangle has two obtuse angles A triangle has three acute angles. A triangle has at least one acute angle.

4. Activity 2: Each student must create a set of 3 numbers that represent triangles. Your mission Is to fool the other members of your group as to which triangle is the fictitious triangle. All students must write 3 sets of numbers on a sheet of paper, that represent three sides of a potential triangle – two sets form a triangle, the third does not. 2. One student stands and reads his/her three sets of numbers written on their paper. 3. Individually, each seated teammate determines which set of segment lengths can’t form a triangle. Each teammate records his/her answer on their piece of paper.

5. 4. The seated teammates show each other their answer and discuss and come to a consensus as to which set of segment lengths cannot form a triangle. 5. If the seated teammates gets the answer correct, the student standing praises them. 6. If the seated teammates gets the answer incorrect, then the standing teammate coaches the team. The seated teammates then praise the standing teammate for challenging them.