# Tuesday 8 January

Welcome back to school!

In Onenote you can find the plan for week 2 – 10.

In Sharepoint you can find summaries for every topic included in the syllabus.

Today we will go through two examination questions involvning:

– Pythagoras Theorem
– Right angled trigonometry
– Non-right angled trigonometry

The questions can be found in Sharepoint, question 2 and 3.

Remember:

• Pythagoras Theorem can only be applied on right angled triangles, and only to find length of a side.
• ”SOH CAH TOA” can only be applied on right angled triangles, and involves relations between angles and length of sides.
• Sine rule and Cosine rule are applied on non-right angled triangles.
• Use Sine rule, when given:
– Two angles and one side (to find length of another side). (If you know two angles, you also know the third…)
– Two sides and a non-included angle (to find the size of another angle).
• Use Cosine rule when given:
– Two sides and an included angle (to find the length of the third side).
– Three sides (to find the size of an angle).