I have a trig question where for this right triangle, only the angles of 90, 18, and 72 degrees are given. It asks to find one of the sides. The answer is written beside the question (the answer's 1.0). Is it possible to solve this using only the angles, or does the answer have to be used?
(Sorry if the answer is really simple, I've forgotten everything from last year)
2007-09-15 22:08:43 · 5 answers · asked by FlyingPenguins 3 in Science & Mathematics ➔ Mathematics
Hi,
No you can not solve for sides of a triangle with only angles because when you know that you have either 2 or 3 pairs of corresponding angles in the 2 triangles that are congruent, the triangles are similar. That means their angles are congruent, but their sides are proportional.
For instance if you had a right triangle with angles of 36.87°, 43.13°, and 90°. the sides could be 3,4, and 5. BUT, they could also be 6,8, and 10 OR 33, 44, and 55. So you can see information about just 3 angles is not sufficient to be able to solve for the lengths of the sides of the triangle.
I hope that helps!! :-)
2007-09-15 22:18:56 · answer #1 · answered by Pi R Squared 7 · 1⤊ 0⤋
Solve Right Triangle
2016-10-02 00:33:13 · answer #2 · answered by ? 4 · 0⤊ 0⤋
Three angles do not define a unique triangle. You must have at least one of the sides.
This is because the angles in a triangle are related to the ratio of the sides.
For example: Take the classic right triangle with sides 3, 4 and 5.
The angles in this triangle will be exactly the same as the angles in a triangle with sides 6, 8 and 10 because the ratio of the sides is the same.
2007-09-15 22:16:39 · answer #3 · answered by lhvinny 7 · 1⤊ 0⤋
actually, I think you can solve it with the help of a scientific calculator. just know what trig.function will you use for example where C is the right angle and c is the hypotenuse ; A is the 30 degree angle and side a is the opposite side of the hypotenuse, therefore the trig function to be used is sin (opposite/hypotenuse) so the equation will be :
sinA = a/c
substitute the value of A which is 30 degrees and the equation will be :
sin30 = a/c
just press the trig function in your scientific calculator (sin30 = 1/2) where 1 is a and 2 is c. if there is a need to find b, use the Pythagorean Thereom.
I hope this helps :)
2013-12-15 20:49:00 · answer #4 · answered by Paolo 1 · 0⤊ 0⤋
Actually sin 90 = 1 and so one of the sides is 1.0 (that is the answer given) and other sides will be given by similar formulas.
2007-09-15 22:14:47 · answer #5 · answered by Swamy 7 · 1⤊ 1⤋