Ong Sian Li's answer to Janicewong's Secondary 2 Maths Singapore question.

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Ong Sian Li
Ong Sian Li's answer
32 answers (Tutor Details)
1st
Remember to use Pythagoras theorem.
Split into 2 triangles and use it to get the common factor. :)