Answer:
Granted that uppercase letters are the angles measurements and lowercase letters are the side lengths. I also was unable to round as I don't know to what decimal you need to round to.
First to find the measure of angle B, we must subtract A and C from 180
![180-21-105=54](https://img.qammunity.org/2020/formulas/mathematics/high-school/jn4lchaihubfk9x52h14nxvm0yjhmmidro.png)
B=54
Next, we can use the law of sines in order to find the measures of a and b
As a reminder, The law of sines is
![(a)/(sinA) =(b)/(sinB) =(c)/(sinC)](https://img.qammunity.org/2020/formulas/mathematics/high-school/eqeg5624br7zozax33y3ga75eeegfrcgjs.png)
First, lets solve for b
![(b)/(sin54)=(5)/(sin105) \\\\b=((5)sin54)/(sin105)\\\\b=4.187780119](https://img.qammunity.org/2020/formulas/mathematics/high-school/5qkoxjja91rwgihyx1o987kzzulsmtsozb.png)
Next lets solve for a
![(a)/(sin21)=(5)/(sin105) \\\\a=((5)sin21)/(sin105)\\\\a=1.85504901](https://img.qammunity.org/2020/formulas/mathematics/high-school/l7ahoo7r661yp7hh1xf3k63p6upu7rs5l1.png)