Instruction

1

If you are aware of the length of the side and held her by the height h

**of the triangle**, use the formula S= ?h*a.2

In a right triangle

a) if we know the length of the legs a and b, the formula is S= a*b / 2;

b) if there are inscribed in a rectangle rectangle circle and a circumscribed circle, also known as their radii, then use the formula S=r2 + 2rR.

**, the area**can be found these ways:a) if we know the length of the legs a and b, the formula is S= a*b / 2;

b) if there are inscribed in a rectangle rectangle circle and a circumscribed circle, also known as their radii, then use the formula S=r2 + 2rR.

3

The task is to determine the area

**of a triangle**in which the lengths of all sides scalene**triangle**, is solved using properiter. First find out the perimeter**of the triangle**by the formula p=?(a+b+c). Next, use the formula S=vp*(p-a)*(p-b)*(p-c).4

The task can be specified only the length of one side

**of the triangle**, but it is equiangular, then you'll need the formula S=a2 v3 / 4.5

In terms of the problem known values of angles and lengths of the adjoining sides. For these applications there are of the formula:

a) S=?a*b*sin? - if you know the angle and length of the two sides adjacent thereto;

b) S=c2 / 2*(ctg ? + ctg ?) – here it is necessary to know the length of sides and magnitude of the two angles adjacent to this side;

in) S=c2 *sin ? * sin ? / 2 sin * (? + ?) – if you know the length of a side and the adjacent angles.

g) If you specify only angles and one side, find

a) S=?a*b*sin? - if you know the angle and length of the two sides adjacent thereto;

b) S=c2 / 2*(ctg ? + ctg ?) – here it is necessary to know the length of sides and magnitude of the two angles adjacent to this side;

in) S=c2 *sin ? * sin ? / 2 sin * (? + ?) – if you know the length of a side and the adjacent angles.

g) If you specify only angles and one side, find

**the area**according to the following formula S=A2 *sin ? * sin ? / 2 sin ?, where a is the side opposite the corner ?.6

For tasks where the lengths of all sides and radius of the circumscribed circle, select a formula S= a*b*C / 4R.

7

The task of finding square you are aware of all the angles, and the radius of the circumscribed circle. For this task, use the formula S=2R2 *sin ? * sin ? * sin ?.

8

In addition to the described and inscribed in a circle of triangles is related to one of the sides of the circle. Area in such problems is given by S=(p-b) * rb , where R – properiter

**of triangle**b – side**of the triangle**, rb is the radius of the circle on the b side.