Audrey Lee's answer to Nidia's Secondary 3 E Maths Singapore question.

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Audrey Lee
Audrey Lee's answer
37 answers (Tutor Details)
1st
Hi Nidia, for part (i), use cosine rule to find angle ABC and ACB, then use 180 degrees to minus both angles to get angle BAC. For part (ii), draw a line down to make it a right angle triangle so that we can use sine rule to find the height of the triangle before we use 1/2 X base X height to find the area of the triangle.