Regular or equilateral tetrahedron – all edges are equal, and the faces, respectively, are equilateral triangles.
The formula for the surface area of an equilateral tetrahedron:
where is the a-side
Rectangular tetrahedron – the angle between all three edges at one vertex is straight, i.e. equal to 90°
The formula for the surface area of a rectangular tetrahedron:
where a,b,c are the sides at an angle of 90°, d,e,f are the sides of the base
Solution:
S1 =
=
=
= 0.5
S2 =
=
=
= 0.5
S3 =
=
=
= 0.5
p =
=
=
= 2.115
S4 = √p·(p-d)·(p-e)·(p-f)
= √2.115·(2.115-1.41)·(2.115-1.41)·(2.115-1.41)
= √2.115·0.705·0.705·0.705
= 0.861
S = S1+S2+S3+S4
= 0.5+0.5+0.5+0.861
=
2.361
a: The area of the entire surface of a rectangular tetrahedron equal to 2.361