Question

In ∆ABC, if ∠A = 90°, which is the longest side?

Answer 1

$In∆ABC,$ $\angle A=90°$.
The sum of the other two angles must be such that
$$\begin{gathered} \angle A+\angle B+\angle C=180° \\ \Rightarrow \angle B+\angle C=90°(\because \angle A=90°) \end{gathered}$$

Thus, angles B and C both measure less than 90$°$.
Angle A is the largest in the triangle and the side opposite to it, i.e., BC is the longest.
∴ BC is the hypotenuse of the right triangle ABC.