Trigonometry in the right triangle –

O triangle It is the simplest figure and one of the most important in geometry. It has properties and definitions according to the length of its sides and the measure of its interior angles. As for the sides, the triangle can be classified as follows:

  • Equilateral: has all sides equal in length.

  • Isolsceles: It has two sides of equal length.

  • Scalene: It has all sides with different measurements.

As for the anglesthe triangle can be:

  • Acute angle: It has interior angles less than 90 degrees.

  • Obtusangle: one of the angles is greater than 90°.

  • Rectangle: An angle that measures 90 degrees is called a right angle.

In the right triangle, there are some important relationships. One of them is the Pythagorean theoremwhich says the following: «The sum of the squares of the legs is equal to the square of the hypotenuse”.

Don’t stop now… There’s more after the publicity 😉

The existing trigonometric relationships in the triangle rectangle admit three cases: sine, cosine It is tangent.

Sine = opposite leg
hypotenuse

Cosine = adjacent side
hypotenuse

Tangent = opposite side
adjacent leg

We will determine the relations according to the triangle BAC, which has sides of length a, b, and c.

sineB = B
The

cosineB = w
The

tangentB = B
w

sinC = w
The

cosineC = B
The

tangentC = w
B

By Marcos Noah
Graduated in Mathematics