I don’t understand this. If anyone helps me it would make my day.
(a) Add the three angles to get 10x+70. All angles of any triangle always equals 180 degrees. So 10x+70=180. Subract 180 to 70 and you get 110. 110 divided by 10 is 11 so X=11.
(b) If x=11 then angle BAC is 61 degrees, angle ABC would be 107 degrees, and angle BCA would be 12 degrees.
I don't know about C.
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