Instruction

1

If you know one of the sides of a triangle and the angle between it and the other party, use the trigonometric functions -

**sine**om Ko**sine**ohms. Imagine a right triangle HBC , which angle α is 60 degrees. Triangle HBC is shown in the figure. Since**the sine**, as you know, is the ratio of the opposite leg to the hypotenuse, and**the sine**- ratio of the adjacent leg to the hypotenuse, to solve this problem, use the following relation between these parameters:sin α=NV/Sootvetstvenno, if you want to know the side of a right triangle, let's Express it using the hypotenuse as follows:HB=BC*sin α2

If the problem, on the contrary, given side of a triangle, find the hypotenuse, according to the following ratio between the specified values:BC=HB/sin APO analogy, find the sides of the triangle and using to

**sine**and changing the previous expression in the following way:cos α=HC/BC3

In elementary mathematics there is the concept of the theorem is

**the sine of**s. Guided by the facts which describes this theorem, you can also find the sides of the triangle. In addition, it allows you to find the sides of a triangle inscribed in a circle if the radius is known is known to last. Use the ratio specified below:a/sin of α=b/sin b=c/sin y=2RЭта theorem applicable in the case when given two sides and angle triangle, or given one of the angles of a triangle and the radius described around the circumference.4

An addition theorem

**of the sine of**s, and exist in substantially the theorem for**the sine of**s, which, like the previous one, also applies to the triangles in all three varieties: right angle, acute and obtuse. Guided by the facts, which prove this theorem, we can find the unknown values using the following relationship:c^2=a^2+b^2-2ab*cos α