To know which triangle is a right triangle, we will have to apply the Pythagorean theorem to each of them.
According to the Pythagorean theorem, we have that:

Now, we must check that this holds true for each triangle.
a) For the first triangle A, we have that:
![\begin{gathered} \text{adjacent}^2+opposite^2=hypothenus^2 \\ \Rightarrow(\sqrt[]{2})^2_{}+(\sqrt[]{3})^2=(\sqrt[]{5})^2 \\ \Rightarrow2+3=5 \\ \Rightarrow5=5 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/odw9sp8kkp8i1kqugptnyxd1a1k4f4a0i8.png)
Since both sides of the equation are the same, triangle A is a right triangle
b) For triangle B, we have that:
![\begin{gathered} \text{adjacent}^2+opposite^2=hypothenus^2 \\ \Rightarrow(\sqrt[]{3})^2_{}+(\sqrt[]{4})^2=(\sqrt[]{5})^2 \\ \Rightarrow3+4=5 \\ \Rightarrow7=5 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/twf7nrb35m09l5eti42vfaoqnjlahys91g.png)
Since both sides of the equation are not the same, triangle B is NOT a right triangle
c) For triangle C, we have that:

Since both sides of the equation are not the same, triangle C is NOT a right triangle
d) For triangle D, we have that:

Since both sides of the equation are not the same, triangle D is NOT a right triangle
e) For triangle E, we have that:

Since both sides of the equation are the same, triangle E is a right triangle
Therefore, only triangles A and E are ri