standard_description: Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.
problem_activity: Task
The goal of this task is to estimate the measure of angles in triangles with integer side lengths.
What are the angle measures in a triangle whose three sides each have length of one unit?  Explain.
What are the approximate measures of the three angles in a triangle whose side lengths are 3, 4, and 5 units respectively? Explain.
What are the approximate angle measures of the three angles in a triangle whose side lengths are 2, 3, and 4 units respectively?


aligns: no