I1.2 If $a$ copies of a right-angled isosceles triangle with hypotenuse $\sqrt{2} \mathrm{~cm}$ can be assembled to form a trapezium with perimeter equal to $b \mathrm{~cm}$, find the least possible value of $b$. (give the answer in surd form).
The perimeter $=6+2 \sqrt{2} \approx 8.8$ or $2+4 \sqrt{2} \approx 7.7$
The least possible value of $b=2+4 \sqrt{2}$