2. The sum of all the interior angles of a triangle is 180*. Example: 90* * 60* + 30* - 180"

3. Finding the angle between two sides of a right triangle using a hand-held calculator; for example, if you want to find angle a and:

If A and B are known, divide A/B and press ARC TAN (or TAN-1).

If A and C are known, divide A/C and press ARC SIN (or SIN-1).

If B and C are known, divide B/C and press ARC COS (or COS-1).

4. Finding the length of the sides of a right triangle knowing at least one side and the angle between two sides, using a hand-held calculator:

To find the length of side C

Knowing B: Divide B by the COS of angle a Knowing A: Divide A by the SIN of angle a

To find the length of side A

Knowing B: Multiply B by the TAN of angle a Knowing C: Multiply C by the SIN of angle a

To find the length of side B

Knowing A: Divide A by the TAN of angle a Knowing C: Multiply C by the COS of angle a

"«" tafle known in degrees

"«" tafle known in degrees

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