Question 149459
In this equation you can use the law of sines...

a       b
__   =  __
SinA    SinB

you are given both angle B and Side B
From, B=20 and C=90, you can find out what A equals by subracting it from 180

180-20-90= 70... A=70
so...

10      a                 Cross multiply so you get:                         
__   = __                 10Sin70=Sin20a so..... 
Sin20  Sin70              10Sin70
                          _______  =a
                          Sin20 

          Therefore you'll get 8.476.... or 8.5 rounded=a

Now that you have a, you can find c with a2+b2=c2

(8.5)2+(10)2=c2
172.25=c2
{{{c=sqrt(172.25)}}}
c=13.1 rounded

Now you have all your angles and all of your lengths!!! :)