Answer:
The answer to your question is:
a) 240 and 300°
b) 120 and 240°
Explanation:
You can see the right triangle below (sorry for my handwriting)
I suggest you to memorize the right triangles for 30°, 60° and 45°, they will be very useful.
To solve these questions, you need to work with the right triangle of 60°.
a)
Remember that sine Ф = opposite side / hyp
then sine 60 = √3 / 2 the answer is 60 but it is negative so you need to look for these angles in thtethird and forth quadrangles.
third q = 180 + 60 = 240° forth q = 360 - 60 = 300°
b)
Work with the same triangle
sec Ф = hyp / adjacent side
sec 60 = 2 / 1 = 2 the answer is 60°
but as it is negative you have to look for angles in the second and third quadrangle.
They will be 180 -60 = 120° and 180 + 60 = 240°