Triangle Rules/Special Right Triangles

Question 1

Side-Angle Inequality

Answer 1

the longest side of a triangle is opposite the largest angle

Question 2

Triangle Inequality

Answer 2

the sum of the lengths of any two sides of a triangle must be greater than the length of the third side

Question 3

Two triangles are similar…

Answer 3

if their corresponding angles are equal and their corresponding sides are proportional

Question 4

Pythagorean Theorem

Answer 4

a^2+b^2=c^2
only works with right triangles

Question 5

45-45-90 Triangle

Answer 5

Hypotenus has length x root 2
Sides have length x
Often used in problems involving squares (two congruent 45-45-90s)

Question 6

30-60-90 Triangle

Answer 6

Short leg length x
Long leg length x root 3
Hypotenuse length 2x
Often used in problems involving equilateral triangles (two equivalent 30-60-90s)