MYTUTOR SUBJECT ANSWERS

310 views

How to use trigonometry to find angles or lengths

Before starting any calculations it makes sense for the new practitioner to use the handy "soh-cah-toa" rule which means that you use:

- sine with the opposite and hypotenuse sides to the angle.

-cosine with the adjacent and hypotenuse sides to the angle.

-tangent with the opposite and adjacent sides to the angle.

The rules are all formulated such that sin(x) = (opposite side length)/(hypotenuse length) where I have used x to denote the angle. The cosine and tangent follow in the same pattern. To find one of the three bits in the equation, you simply rearrange to get the unknown on its own and then (hopefully) just plug this into your calculator. In the case where you search for the angle you must get your trigonometric function on its own and then use the inverse function to both sides of the equation so now you will have for example :

x = arcsin[(opposite side length)/(hypotenuse side length)] where x is the angle and arcsin[] denotes the inverse of sine.

Similarly you would use this method with tangent and cosine.

Bradley L. A Level Further Mathematics  tutor, A Level Maths tutor, G...

1 year ago

Answered by Bradley, a GCSE Maths tutor with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist

328 SUBJECT SPECIALISTS

£18 /hr

Madeleine P.

Degree: Economics (Bachelors) - Durham University

Subjects offered: Maths, -Personal Statements-

Maths
-Personal Statements-

“About me I am reading Economics at Durham University. I have always had a passion and love for Mathematics and really enjoy now using it at degree level when tackling real world problems. I am very patient and freindly and have a desi...”

£18 /hr

Emma W.

Degree: Natural Sciences (Bachelors) - Durham University

Subjects offered: Maths, Physics+ 2 more

Maths
Physics
Chemistry
Biology

“Hi! I'm Emma and I'm a second year Natural Sciences student from Durham University, which means I've studied biology, physics and maths at university level. I have a very friendly tutoring style as I believe students are most able to ...”

MyTutor guarantee

£18 /hr

Phoebe W.

Degree: Classics (Bachelors) - Bristol University

Subjects offered: Maths, Latin+ 1 more

Maths
Latin
Classical Greek

“Hello!! I am a 2nd year student reading Classics at Bristol University. I have always loved studying these languages and hope that I can inspire you to continue on this epic journey that mirrors Odysseus' - long and difficult at times...”

MyTutor guarantee

About the author

Bradley L.

Currently unavailable: no new students

Degree: Mathematics and Physics (Masters) - Bristol University

Subjects offered: Maths, Physics+ 1 more

Maths
Physics
Further Mathematics

“I am a patient and friendly person. I love mathematics and physics and I would love to help people get through the sticking points of these subjects.”

MyTutor guarantee

You may also like...

Other GCSE Maths questions

How do I know how many roots a quadratic equation has?

Solve these simultaneous equations. 5x + 2y = 20 and x + 4y = 13.

Find the highest common factor of 432 and 522

What is the Pythagoras Theorem?

View GCSE Maths tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok