The first one can be done by Pythagoras theorem such as [tex]12^2=9^2+x^2[/tex] then [tex]x^2=63[/tex] then [tex]x= \sqrt{63} [/tex]
The second one can also done by Pythagoras theorem, note that this is isosceles triangle so [tex]y=z[/tex], again by using Pythagoras theorem [tex]15^2=y^2+z^2=y^2+y^2 or =z^2+z^2[/tex] then [tex]225=2y^2[/tex] then [tex]y= \sqrt{\frac{225}{2} }[/tex]
For the last one can also done by property of 30-60-90 triangle. [tex]w=8 \sqrt{3} [/tex][tex]k=2.8=16[/tex]
