Triangle inequality, parallelogram equality

In summary, the triangle inequality theorem states that for any triangle, one side must be less than the sum of the other two sides, but greater than the difference between the two sides. Similarly, the parallelogram inequality states that for any parallelogram, one side must be less than or equal to the sum of the other two sides.
  • #1
asdf1
734
0
what does a triangle have to do with triangle inequality, and what does a paralllelogram have to do with parallelogram equality?
@@a
 
Physics news on Phys.org
  • #3
i'm still confused:
"triangle inequality is the theorem stating that for any triangle, the measure of a given side must be less than the sum of the other two sides but greater than the difference between the two sides."
yet "|x+y| ≤ |x|+|y| " shouldn't mean "|z|≤ |x|+|y| "?
 
  • #4
asdf1 said:
i'm still confused:
"triangle inequality is the theorem stating that for any triangle, the measure of a given side must be less than the sum of the other two sides but greater than the difference between the two sides."
yet "|x+y| ≤ |x|+|y| " shouldn't mean "|z|≤ |x|+|y| "?

If you think of x and y as vectors in space they will form a triangle with a third vector that is the vector sum x+y so the inequality makes sense.
 
  • #5
thank you very much!
 

1. What is the Triangle Inequality Theorem?

The Triangle Inequality Theorem states that the sum of any two sides of a triangle must be greater than the length of the third side. In other words, the longest side of a triangle must be shorter than the sum of the other two sides.

2. How is the Triangle Inequality Theorem used?

The Triangle Inequality Theorem is used to determine if three given side lengths can form a valid triangle. If the theorem is not satisfied, then the given side lengths cannot form a triangle.

3. What is the Parallelogram Equality Theorem?

The Parallelogram Equality Theorem states that opposite sides of a parallelogram are congruent, and opposite angles are also congruent. This means that a parallelogram has two pairs of parallel sides and two pairs of congruent angles.

4. How is the Parallelogram Equality Theorem used?

The Parallelogram Equality Theorem is used to prove that a given quadrilateral is a parallelogram. By showing that opposite sides are congruent and opposite angles are congruent, we can conclude that the figure is indeed a parallelogram.

5. Can the Triangle Inequality Theorem and the Parallelogram Equality Theorem be used together?

Yes, these two theorems can be used together to determine if a given figure is a parallelogram. If the Triangle Inequality Theorem is satisfied for all three pairs of sides and the Parallelogram Equality Theorem is satisfied for opposite sides and angles, then the figure is a parallelogram.

Similar threads

  • Precalculus Mathematics Homework Help
Replies
14
Views
538
  • Introductory Physics Homework Help
Replies
5
Views
252
  • Precalculus Mathematics Homework Help
Replies
6
Views
2K
  • General Math
Replies
2
Views
1K
  • Precalculus Mathematics Homework Help
Replies
11
Views
866
  • Precalculus Mathematics Homework Help
Replies
9
Views
2K
  • Precalculus Mathematics Homework Help
Replies
6
Views
576
  • Precalculus Mathematics Homework Help
Replies
5
Views
748
Replies
1
Views
674
  • Precalculus Mathematics Homework Help
Replies
7
Views
1K
Back
Top