Triangle similarity

[Loki123]

I am confused about triangle similarity. What is the correct way to show relations of the triangle sides?

 

[Dr.Peterson]

I am confused about triangle similarity. What is the correct way to show relations of the triangle sides? View attachment 32245

Both are equivalent, and therefore correct. If you cross-multiply in each case, you will see this; both yield a₁b = ab₁.

The first form says that the ratio within one triangle equals the corresponding ratio within the other.

The second says that each ratio of corresponding sides is the same, and can be extended to cover all three pairs: a:a₁ = b:b₁ = c:c₁.

The second form is probably more commonly taught, because of that extension.

 

[Loki123]

Both are equivalent, and therefore correct. If you cross-multiply in each case, you will see this; both yield a₁b = ab₁.

The first form says that the ratio within one triangle equals the corresponding ratio within the other.

The second says that each ratio of corresponding sides is the same, and can be extended to cover all three pairs: a:a₁ = b:b₁ = c:c₁.

The second form is probably more commonly taught, because of that extension.

okay, got it ! thanks