We havae a triangle with the next measures:
- a = 2
- b = √11
- c = √15
To know if the triangle is acute, right or obtuse we must use the next statement
Now, we must calculate

And then we must compare it with

So,
![\begin{gathered} a^2+b^2 \\ =2^2+(\sqrt[]{11})^2 \\ =4+11 \\ =15 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/7yxvofndku6qbplr834gop44qt7497gv04.png)
And
![\begin{gathered} c^2 \\ =(\sqrt[]{15})^2 \\ =15 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/77j3nyku5n26j1tocgbicc1ltbxt38qe9q.png)
Finally, we can see that

So, it is a right triangle.