1. Drawing Solid
By Novianti

2. Drawing a Tetrahedron T.ABC
Draw line AA‘, in the actual size
From the point A‘ we draw a 30o angle, and draw BC
Connect A and B
Tetrahedron edge length: 6 cm
Frontal plane:TAA‘( A‘ is projection point of point A in line BC.)
Subsided angle: 30 o
Orthogonal ratio is 2 : 3 T
Please pay attention on whether the lines are dashed or no.
Congratulation! We are succeed in drawing the Tetrahedron.
The intersecting point between CC‘ and AA‘ is point T‘.
Find the midpoint of AB using a compass. Named the point C‘
Draw TT’ that perpendicular to AA’
Connect T and A
Connect T and B
Connect T and C
Connect C and C’
Connect A and C B C
Please pay attention on whether the lines are dashed or no.
30o A A’ T’ C’
Note: TT’ is the height of the tetrahedron. We can find the length of TT’ by using Pythagoras’ Theorem in the right triangle TT’A.
Since T’ is the projection of T in line AA’, then AT’ : AA’= 2 : 3
AA’ is the height of equilateral triangle ABC
The actual size of AA‘ is cm
The drawn A’C is
The drawn A’B = The drawn A’C
The drawn TT’= the actual size of TT’= cm