ANSWER:
The correct choices are B and C
STEP-BY-STEP EXPLANATION:
For it to be a right triangle, it must fulfill the Pythagorean theorem that says the following:
[tex]a^2+b^2=h^2[/tex]We apply for each case, like this
[tex]\begin{gathered} 1^2+5^2=26^2\rightarrow26=676\rightarrow\text{ This is false therefore it is not a right triangle} \\ 1.5^2+2^2=2.5^2\rightarrow6.25=6.25\rightarrow\text{ This is true therefore it is a right triangle} \\ 4^2+4^2=(\sqrt[]{32})^2\rightarrow32=32\rightarrow\text{ This is true therefore it is a right triangle} \end{gathered}[/tex]