Answer
Each shorter side = $2\sqrt 2$
Work Step by Step
In a 45°–45°–90° triangle,let's assume that each of the shorter side is 'x'. then as per Pythagorean theorem-
$longest side^{2}$ = $x^{2} + x^{2}$ = 2$x^{2}$
Therefore longest side = $x\sqrt 2$
Given that longest side is $ 4$
Hence
$x\sqrt 2$ = $ 4$
Dividing both the sides by $\sqrt 2$
x = $\frac{4}{\sqrt 2}$
or
x = $\frac{2\sqrt 2\sqrt 2}{\sqrt 2}$ = $2\sqrt 2$
Thus each shorter side = $2\sqrt 2$
