For a start we will agree about designations. A leg call the party of a rectangular triangle which prilezhit to a right angle (i.e. makes a corner of 90 degrees with other party). Lengths of legs we will agree to designate an and b. Sizes of acute angles of a rectangular triangle, opposite to legs, we will call A and B respectively. A hypotenuse call the party of a rectangular triangle which protivolezhit to a right angle (i.e. is opposite to a right angle, with other parties of a triangle forms acute angles). We will designate length of a hypotenuse through page. We will designate Iskomaya Square through S.
Instruction
1. Define what sizes of the considered rectangular triangle are known to you. Proceeding from it, choose proper expression.
2. Calculate the area of a rectangular triangle as a half of the work of legs, i.e. S=0.5*a*b in case their lengths are known to you.
3. Calculate the area by formula S = b*c*sin(A)/2 if to you one of legs (b), a hypotenuse (c), and also a corner (A) between them is set. This formula is fair not only for a rectangular triangle, but for any triangle in general.
4. Apply formula S = (a^2) / (2*tg (A)) in case to you only one of legs (a) is set, but also also opposite the corner (A) is known to this leg. He is familiar "" ^2"" operation of squaring is designated.
5. Use a formula S=(a^2) *tg (B)/2 d a case if to you only one of legs (a) is set, but also also adjacent the corner (B) is known to this leg.
6. Calculate to ploshchat on formula S = a*sqrt (c^2 – a^2)/2 if sizes of a leg (a) and a hypotenuse (c) are known to you. The operation sqrt is designated by a square root.
7. Use expression of S = (c^2) of *sin (A) *cos(A)/2 if the hypotenuse (c) and one of acute angles (A) is set.