Can a 30-60-90 triangle have lengths 3,4,5?? If not, then why do so many examples online use a 3,4,5 triangle to find the sine of 30

Question

Trigonometry

Answer 1

The 3-4-5 triangle is the easiest of several Pythagorean triples. Others are 5-12-13 and 8-15-17. (These numbers are sides of right triangles.)

 

Students should memorize the relative sizes of the sides of the special 30-60-90 triangle, and also those of the isosceles right triangle, in order to become efficient in solving trigonometry and physics problems, where 30 degree, 45 degree, 60 degree angles proliferate.

Answer 2

No, it can not. I would not use a 3-4-5 triangle to find the sine of 30 degrees because its side angles are approximately 37 and 53 degrees.