Its not a full questions...... send the full question
Answer:
Always
Step-by-step explanation:
The definition of a perpendicular line is that it intersects another at a 90 degree angle. Using this, by verticals, the opposite corner angle must also be 90-degrees, and since one side of a line is 180 degrees, 180-90 = 90, which ensure the rest of the angles will be 90 degrees too.
Answer:
option c 1000
Step-by-step explanation:
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Plane acb
plane bac
plane bca
plane cab
plane cba
