Triangle Calculator
A triangle is a polygon with 3 sides. Every triangle consists of three sides and angles accordingly. In the case there is a right triangle the side that is opposite to the right angle is called the hypotenuse and the other two sides are the legs.
The Area of a Triangle
If the length of the base (b) and the height of triangle (h) are known the formula is as follows:
Area = ½ bh,
If the length of two sides (x,y) and the angle between them are known the formula is as follows:
Area = ½ xy sin(c) = ½ xz sin(a) = ½ yz sin(b)
The AAS theorem. If you specify two angles A
and B
and a side a
the formula is as follows:

The ASA theorem. If you specify an angle A
, a side c
, and an angle B
the formula is as follows:

The ASS theorem. If there is a triangle with two sides,a
the smaller and c
the larger, and angle A
is known, acute and opposite a
, if sin A < a/c
, there are just two possible triangles. If sin A = a/c
, there is just one possible triangle. If sin A > a/c
, there are no possible triangles.
The SAS theorem. If is the base length (a) and is the height (h) are known the formula is as follows:

The SSS theorem. If all three sides and the circumradius (R) are known, the formula is as follows:

Use these calculators to compute area of a triangle.
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