Write the ordered pair that represents yz then find the magnitude of yz y(5,,6)

The ratio of the measures of the three angles in a triangle is 2: 9: 4. find the measures of the angels

Hi, can anyone show me how to do this problem? 100 points for this. in advance

What would be the reasons for lines 3 and 4? a. addition property; subtraction property b. addition property; solve c. substitution property; subtraction property d. substitution property; prove