Solving a triangle means determining the measures of all of the sides and angles.
A right triangle is generally easier to solve than most other kinds. Trigonometric definitions relate angles to pairs of sides. The Pythagorean theorem relates the sides to each other. To completely solve a right triangle, you must know a minimum of
- one side and one acute angle, or
- two sides.
You already know that one angle is 90 degrees, so these are equivalent to
- 1 side and 2 angles, or
- 2 sides and 1 angle.
With this information, or knowing 3 sides, you can completely solve any triangle.
In short, you must know 1 side and any 2 of the remaining 5 descriptors.
A right triangle is generally easier to solve than most other kinds. Trigonometric definitions relate angles to pairs of sides. The Pythagorean theorem relates the sides to each other. To completely solve a right triangle, you must know a minimum of
- one side and one acute angle, or
- two sides.
You already know that one angle is 90 degrees, so these are equivalent to
- 1 side and 2 angles, or
- 2 sides and 1 angle.
With this information, or knowing 3 sides, you can completely solve any triangle.
In short, you must know 1 side and any 2 of the remaining 5 descriptors.
