In the plane geometry of junior high school mathematics, we have the true proposition that "two straight lines perpendicular to the same straight line are parallel".

Proved as follows:

Proof: known: a⊥c, b⊥c,

Proof: a ∨ b.

Proof: As shown in the figure:

∵a⊥c,b⊥c，

∴∠ 1=90 ,∠2=90 ,

∴∠ 1=∠2,

Therefore, a ∑ b.

Is a false proposition in space.

Hope to adopt, if you don't understand, welcome to ask questions.