MHB Why Isn't the Law of Tangents Taught in High School Trigonometry?

[mathdad]

When students are first taught trigonometry in public high schools across the USA, they eventually learn about the law of sines and law of cosines. However, the law of tangents is not taught.

1. What is the law of tangents?

2. What is the usefulness of this law?

3. Why do YOU think the law of tangents in not taught in most trig courses?

 

[MarkFL]

When students are first taught trigonometry in public high schools across the USA, they eventually learn about the law of sines and law of cosines. However, the law of tangents is not taught.

1. What is the law of tangents?

I have heard of it, but never learned it or used it. I had to look it up:

Law of tangents

2. What is the usefulness of this law?

It can be used in any case where two sides and the included angle, or two angles and a side, are known.

3. Why do YOU think the law of tangents in not taught in most trig courses?

Perhaps because it is equivalent to the law of sines, which is simpler to recall? :D

 

[mathdad]

I have heard of it, but never learned it or used it. I had to look it up:

Law of tangents
It can be used in any case where two sides and the included angle, or two angles and a side, are known.
Perhaps because it is equivalent to the law of sines, which is simpler to recall? :D

I asked three questions in the other post about the car distance. I look forward to your answers.