In triangle XYZ, ∠XYZ = 15

^{o}, ∠XZY = 45^{o}and lXYl = 7 cm. Find lYZl.-
**A.**

14√2 cm -
**B.**

(7left(frac{sqrt{6}}{2}right)) -
**C.**

7√2 cm -
**D.**

7 cm

##### Correct Answer: Option B

##### Explanation

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

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

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