Answer:
1) d) clarinet, flute and trumpet
2) b) 6
3) c) 21 < d < 147
Explanation:
1) The angle formed by trumpet and clarinet is 180-45-68 = 67
So the angles are
trumpet and flute : 45
flute and clarinet : 68
clarinet and trumpet : 67
The side opposite to the smallest angle is the shortest and the side opposite to the largest angle is the longest
The smallest angle is between trumpet and flue and the side opposite to this will be clarinet. So clarinet will be the shortest side
The largest angle is between flute and clarinet and the side opposite to this will be trumpet. So trumpet will be the losgest side
Sorting for least to greatest: clarinet, flute and trumpet
2) a = 14 and b = 8
The third side, c lies between |a-b| and |a+b| (triangle inequality theorem))
c lies between |14-8| and |14+8|
i.e 6 and 22
ie. 6 < c < 22
Therefore c ≠ 6 (option b)
3) a = 84 and b = 63
The third side, d lies between |a-b| and |a+b| (triangle inequality theorem))
d lies between |84-63| and |84+63|
i.e 21 and 147
ie. 21 < d < 147 (option c)