Trigonometry grade 12 revision: CAST diagram

Trigonometry grade 12 revision question. You need to construct a triangle on the CAST diagram.

[mohammedriyaadhfarouk]

For sin(140), I expanded it using sin(70+70) and I managed to get the same answer

[nobuhlengcobo]

For cos(110) I did it as cos(90+20)=sin20 =k/1 before watching the way you did it sir😊

[moneuamber]

Sir for cos(110), I think you made a mistake cause you simplified for -cos70 while the original angle that was given wa sin(20). You can only solve for anything that has the angle 20 in it

[_dayswshawty]

I got -k as an answer but instead of using the other angle I used co-functions to get my answer. Is that still correct?

[princemasuku]

hey kevin remember when u taught co functions in the grade 11 course? i just noticed that the reason why sin20=k and cos70=k is because 70+20=90 coz of the co-function's property
how cool is that🤣🤣🤣🤣🤣🤣🤣🤣

[kirengovender]

could we have used co functions for a) kev?

[sparkle]

How to get sin 140 using sinAcosA=1/2 sin A?

[Warrenpillay]

Sir shouldn't cos(170⁰) be adjacent over hypotenuse? Your answer is opposite over hypotenuse. I'm confused at that point