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The 180° Rule
The 180° Rule
Every triangle in the universe has angles that add up to exactly 180°. It doesn't matter if it's tiny or massive, flat or tilted - the three angles ALWAYS sum to 180°. This is the most important triangle fact you'll ever learn!
Visual: Types of Triangles
Tip: Equal sides have matching tick marks, equal angles have matching arcs
Now try it yourself
Quiz · Question 1 of 12
What is the sum of the interior angles of any triangle?
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