Triangle Inequality Theorem and Angle Sums

The shortest side length is opposite the largest angle.

The sum of the two short sides are greater than the length of the longest side.

The longest side length is opposite the largest angle.

The largest angle is more than 90 degrees.

The three angles add up to 180 degrees.

The three angles are all acute angles.

The Sum of the three sides equals 180.

3, 4, 7

12, 4, 7

4, 7, 9

12, 7, 3

360 degrees

90 degrees

180 degrees

270 degrees

90, 45, 45: Right, Isosceles Triangle

20, 20, 60: Acute, Isosceles Triangle

60, 60, 60: Acute, Equilateral Triangle

120, 90, 70: Right, Obtuse Triangle

120, 40, 20: Obtuse, Scalene Triangle

30, 60, 80: Acute, Scalene Triangle

3, 4, 5

8, 9, 10

7, 7, 7

4, 4, 8

6, 3, 2

12, 8, 8