MHB Find the Range of $n$ for $\triangle ABC$

  • Thread starter Thread starter Albert1
  • Start date Start date
  • Tags Tags
    Range
Click For Summary
In triangle ABC, the sum of two angles is given as n degrees, with the largest angle α and the smallest angle γ satisfying the condition α - γ = 24 degrees. To find the range of n, it is established that the angles must adhere to the triangle inequality and the properties of angles in a triangle. The resulting range for n is determined to be between 104 degrees and 136 degrees. This conclusion is confirmed as correct within the context of the problem. The analysis highlights the relationships between the angles and their constraints in triangle ABC.
Albert1
Messages
1,221
Reaction score
0
$\triangle ABC ,\,\, given :$
(1) sum of its two angles=$n^o$
(2) if $\alpha$ is the largest angle
and $\gamma $ is the smallest angle ,we have :$\alpha - \gamma =24^o$
please find the range of $n$
 
Mathematics news on Phys.org
Albert said:
$\triangle ABC ,\,\, given :$
(1) sum of its two angles=$n^o$
(2) if $\alpha$ is the largest angle
and $\gamma $ is the smallest angle ,we have :$\alpha - \gamma =24^o$
please find the range of $n$

The boundaries are determined by $\beta$ which much be between $\alpha$ and $\gamma$.
In the extreme cases, we have:
$$\alpha = \beta, \gamma=\alpha -24^\circ \qquad\qquad (1)$$
respectively
$$\alpha, \qquad \beta = \gamma=\alpha -24^\circ \qquad (2)$$

Since the sum of the angles must be $180^\circ$, we get:
in case (1): $3\alpha - 24^\circ = 180^\circ \Rightarrow \alpha = \beta = 68^\circ, \gamma=44^\circ$
in case (2): $3\alpha - 48^\circ = 180^\circ \Rightarrow \alpha = 76^\circ, \qquad \beta = \gamma=52^\circ$

It is not clear to me of which two angles $n$ would be the sum.
If it is about $\alpha + \gamma$, the range of $n$ is $[112^\circ, 128^\circ]$.
If it is about any 2 angles, the range of $n$ is $[104^\circ,136^\circ]$.
 
I like Serena said:
The boundaries are determined by $\beta$ which much be between $\alpha$ and $\gamma$.
In the extreme cases, we have:
$$\alpha = \beta, \gamma=\alpha -24^\circ \qquad\qquad (1)$$
respectively
$$\alpha, \qquad \beta = \gamma=\alpha -24^\circ \qquad (2)$$

Since the sum of the angles must be $180^\circ$, we get:
in case (1): $3\alpha - 24^\circ = 180^\circ \Rightarrow \alpha = \beta = 68^\circ, \gamma=44^\circ$
in case (2): $3\alpha - 48^\circ = 180^\circ \Rightarrow \alpha = 76^\circ, \qquad \beta = \gamma=52^\circ$

It is not clear to me of which two angles $n$ would be the sum.
If it is about $\alpha + \gamma$, the range of $n$ is $[112^\circ, 128^\circ]$.
If it is about any 2 angles, the range of $n$ is $[104^\circ,136^\circ]$.
it is about any 2 angles, the range of $n$ is $[104^\circ,136^\circ]$
your answer is correct :)
 
Thread 'Erroneously  finding discrepancy in transpose rule'
Obviously, there is something elementary I am missing here. To form the transpose of a matrix, one exchanges rows and columns, so the transpose of a scalar, considered as (or isomorphic to) a one-entry matrix, should stay the same, including if the scalar is a complex number. On the other hand, in the isomorphism between the complex plane and the real plane, a complex number a+bi corresponds to a matrix in the real plane; taking the transpose we get which then corresponds to a-bi...

Similar threads

  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 5 ·
Replies
5
Views
3K