Depends on what information you have and what you require.
If you have all three sides, there are different formulae to find the perimeter, angles and area.
If you have two sides and an angle (depending on the angle) you have formulae for the remaining side and then perimeter and area.
If you have a side and two angles there are formulae to find the missing sides and then perimeter and area.
There are other possibilities: you have the altitude and require the area; etc.
irregular triangle
Irregular triangle
It can be either
wadud
A tetrahedron is not an irregular triangle, it is a three dimensional shape, the simplest form of pyramid, with 4 triangular sides.
A scalene triangle is irregular. Only an equilateral triangle is regular.
It is irregular
irregular triangle
Irregular triangle
irregular
Irregular triangle
nope
It can be either
wadud
No.
A tetrahedron is not an irregular triangle, it is a three dimensional shape, the simplest form of pyramid, with 4 triangular sides.
There is no formula. That's why it's called irregular!