Welcome GCSE Maths

What is x?

What is x?

What is ‘a’?

Trigonometry We can use trigonometry to find missing angles and lengths of triangles Trigonometry uses three functions, these are called: Sine (shortened to Sin and pronounced “sign”) Cosine (shortened to Cos) Tangent (shortened to Tan) We will start working with right angled triangles

Labelling the sides Hypotenuse Before we can use Sin, Cos and Tan we need to be able to label the sides of a right angled triangle The longest side, the one opposite the right angle, is called the Hypotenuse Hypotenuse

https://www.youtube.com/watch?v=jwswKGw0DuM

But if we are working with this angle, we label the sides like this... What we call the other two sides will change depending on which angle we are working with, for example.. If we are given (or need to work out) this angle, we label the other sides like this.. Opposite Adjacent But if we are working with this angle, we label the sides like this... ϴ Opposite Adjacent

What is the side marked with an X? ϴ Adjacent Opposite Hypotenuse

What is the side marked with an X? ϴ X Adjacent Opposite Hypotenuse

What is the side marked with an X? ϴ Adjacent Opposite Hypotenuse

What is the side marked with an X? ϴ X Adjacent Opposite Hypotenuse

What is the side marked with an X? ϴ Adjacent Opposite Hypotenuse

What is the side marked with an X? ϴ Adjacent Opposite Hypotenuse

Stages for Trigonometry in right-angled triangles Label sides Decide on formula to use Write formula Calculate formula, (do the sum) Write your answer as stated in the question. Triangles of knowledge

Triangles of knowledge SIN COS TAN

Example 1 7cm x Label sides Decide on formula to use Write formula 42˚ 7cm x Label sides Decide on formula to use Write formula Calculate formula, (do the sum) Write your answer as stated in the question.

Example 2 9cm t Label sides Decide on formula to use Write formula 53˚ 9cm t Label sides Decide on formula to use Write formula Calculate formula, (do the sum) Write your answer as stated in the question.

Example 3 y 11cm Label sides Decide on formula to use Write formula 53˚ 11cm y Label sides Decide on formula to use Write formula Calculate formula, (do the sum) Write your answer as stated in the question.

Example 4- what to do if finding an angle Label sides Decide on formula to use Write formula Calculate formula, (do the sum). Write your answer as stated in the question. 8cm 5cm X

what to do if finding an angle Example 5 what to do if finding an angle Label sides Decide on formula to use Write formula Calculate formula, (do the sum) Write your answer as stated in the question. X 32 cm 56 cm

Applying the knowledge Matching activity Revision workbook Exam style questions Remember the stages… Label sides Decide on formula to use Write formula Calculate formula, (do the sum) Write your answer as stated in the question.

Reflection What went well? What could be better? What did I learn? What still puzzles me?