In triangle XYZ XYZ 15o XZY 45o and lXYl 7 cm F... - JAMB Mathematics 2006 Question

∠yxz = 180 - (45 + 15)

= 180 - 60

= 120^o

Using sine rule

(\frac{x}{sinx}=\frac{7}{sinz}\

\frac{x}{sin 120}=\frac{7}{sin 45}\

x=\frac{7 sin 120}{sin45}\

x=\frac{7sin(180-120)}{sin 45}\

x=\frac{7 sin 60}{sin 45}=\left(7\left(\frac{\sqrt{3}}{2}\right)\div \frac{1}{\sqrt{2}}\right)\

x =\left(7\left(\frac{\sqrt{3}}{2}\right)\div \frac{1}{\sqrt{2}}\right)\

x = 7\left(\frac{\sqrt{6}}{2}\right))