2. it can't have three because one of them is a right triangle do D doesn't add up. It can't have 0 because an obtuse angle plus a right angle would go over 180 degrees. So, the most it can have is 2 acute for example 90(right angle) 30(acute) and 60 (acute) is a possible answer. Also, a right angle can only have two acute angles since an obtuse angle would put it over 180 which was already stated
20x-28+12=16x+24 (i distributed the 4 to get this)
20x-16=16x+24 (added -28 & 12)
4x=40 (Subtracted 16x from both sides and added 16 to both sides)
(divide by 4 on both sides)
x=10
Answer:

Step-by-step explanation:
The Law of Cosines is given as:
.
Plugging in given values, we get:
.