Someone explain this (Geometry)?

Question

You can determine angles of a triangle if the ratios of the sides are given, such as in the format of A : B : C. right?

A*180/(A+B+C), B*180/(A+B+C), C*180/(A+B+C)

So let's say I've got a right triangle with the side lengths of 3, 4 and 5. I guess I have to convert these lengths to ratios. This is where I'm confused. Do I use side length 3 as the reference ratio to the other sides? Meaning 3/3, 4/3, and 5/3? But those don't work when I try to multiply the ratios back into angles because none of them equal to 90, which I know exists because its a right triangle.

Answer 1

Whoah, hold on there, Tex! This just is NOT TRUE.

That is to say, you *can* determine the angles if the ratios of the sides are given, but the angles are NOT proportional to the ratios of the sides! (For example, you know in a 30-60-90 triangle that the ratios of the sides aren't 1:2:3!)

Rather, the angles can be calculated by the trigonometric functions. If you're in a geometry class and not a trig class, and you haven't yet seen trig functions, then there is no way for you to determine the angles given the lengths of the sides, except by recognizing certain patterns. (E.g., angles in an equilateral triangle, or a right isoceles, or a 30-60-90.)

In particular, the two non-right angles of a 3-4-5 triangle are not rational numbers (fractions) when written in degrees (or even radians).

Sorry!

Answer 2

Let's label the angle, too. The angle opposite side A is a. Its sine (abbr: sin) is A/C , in this case 4/5 or 0.80000. the cosine (abbr: cos) is B/C or 3/5 or 0.60000. The tangent (abbr: tan) is 4/3 or 0.75000 So every triangle with that relationship between sides have the same angles.

Answer 3

Your ratios aren't 3/3, 4/3 and 5/3 but 3/(3+4+5), 4/(3+4+5) and 5/(3+4+5), or 3/12, 4/12, 5/12 = 1/4, 1/3, 5/12

Answer 4

know your common triangles a 3-4-5 triangle is a 30/60/90 triangle.

Answer 5

if your subject have been to have a slope of a million/a million and one element is (7,7) and yet another is (-9,-9) it remains an identical slope and nonetheless an identical y-intersept (0 to that end). In different phrases its on an identical line if the slope is an identical and the y-intercept is an identical. Colllinear potential "factors that 'lie' on an identical line" so ok is in basic terms to mixture you up except there is yet another subject that has ok in it. Lie does advise lie on an identical line