Question

How do I solve this using Sin or Cosine law?

Answer 1

Those two have both two formulas but when dealing with a not-right triangle which is a particular case you use this formula for sines.

$\frac{SinC}{c} =\frac{SinR}{r}$

Substitute

Note: the capital letters are for the angles and the small letter are for the sides.

But since we used side R and there is no angle to substitute. you will basically have to find it by adding the two angles given and subtracting it by 180, which is a 100.

$\frac{Sin(7)}{1.9} =\frac{Sin100}{x}$

now you do the butterfly method or cross multiplication method.

$xsin(7)=1.9sin(100)$

You have to isolate the x

$\frac{xsin(7)}{sin(7)} =\frac{1.9sin(100)}{sin(7)}$

now cancel and plug the right side of the equation into your calculator and u get the answer for the missing side.

$x= 15.35$ or if u want to round it $15.4$

<R = 100 and side CK= 15.35 or 15.4

Hope I helped! ^w^

TheOneAndOnlyLara~