Lets call the smallest angle of this triangle n.
So using that second angle is three times larger than the smallest angle, we can call this 3n.
And using that third angle is 20° larger than the smallest angle we can call this n + 20°
Working with our own knowledge, we know that the interior angles of a triangle all add up to 180°
Taking this and putting this into an equation we can say that:
n + 3n + n + 20° = 180°
which also all adds up to:
5n + 20° = 180°
Next, we must get n by itself so to get this we balance the equation. So we -20° on both sides:
5n = 160°
Finally we can get n by its own by dividing 5 on both sides:
n = 32
Now, we need to find out the measure to the LARGEST angle and using that the smallest angle ,n, is 32 we can use this to work out the second angle ,3n, and third angle ,n + 20°, and now replacing n with 32°.
We can do 3 × 32° which equals to 96° - second angle
And 32° + 20° which is 52° - third angle
And there, we just worked out the largest angle: the second angle = 96°
Answer = 96°
Hope this helped!