how do you do this ?

Answer:
71 degrees
Step-by-step explanation:
The angles in a triangle add to 180 degrees, so
∠M + ∠A +∠T = 180
We know ∠M is 82 degrees, and ∠A is 27 degrees, so we can substitute them in.
82+27+∠T=180
109+ ∠T=180 Combine like terms by adding 82 and 27
109-109+ ∠T=180-109 Subtract 109 from both sides to get ∠T by itself
∠T=71
So, the m∠T is 71 degrees