Question

Find the value of side a on the right triange, given that side B=12cm and side C=15cm

Answer 1

Use Pythagoras's theorem.
$a^{2} + b^{2} = c^{2}$

Now, minus 12 from 15:
15 - 12 = 3,
which you need to square.
So the length of a = 9cm.

You can also do:
$\sqrt{15^{2} - 12^{2} }$
Which gets 9.

Hope this helps.