Question

Angle bisectors TX and UY triangle TUV meet at point I. Find all possible values of angleV if angleTIU = 109. As your answer, enter the number of degrees in angleV. If you find more than one possibility, list the possible values in increasing order, separated by commas.

Answer 1

Check the picture attached.

let m(VTI)= m(ITU)=a and let m(VUI)= m(IUT)=b

Then, in triangle TUV:

2a+2b+c=180°

2(a+b)+c=180°

c=180°-2(a+b)


In triangle TUI:

a+b+109°=180°

a+b=180°-109°=71°

substitute in c=180°-2(a+b):

c=180°-2(a+b)=180°-2*71°=180°-142°=38°