Answer:
firstly a triangle has angle sum of 180°
Explanation:
let all the three angles be x,y and z such that x+y+z =180°
let x= 58° and y =59°
the to calculate for the unknown z angle ;
make z subject of the formula
thus z= 180° -x-y
> z= (180-58-59)°
z= 180-117
z= 63°