finding the value of the unmeasured angle?

Answer 1

Lots of ways, if you have the length of the sides,

sin(x)=opposite/hypotoneus
cos(x)= adjacent/hypotenous
Tan(x) = opposite/adhacent

aslo see 'sin rule' and 'cosine rule'

and pythagerous' theroem

Answer 2

Dear different situations different answers. some could be ;

1. Measuring with protactor.
2. In triangle, 180 - sum of two known angles
3. In Circles, length of arc = (radius)(angle)

hell of other ways.

Answer 3

Subtract the other two angles from 180 in a triangle