1)
[tex]\it \ell_3 = R\sqrt3
\\\;\\ \\\;\\
a_3 = \dfrac{R}{2}
\\\;\\ \\\;\\
\mathcal{A}_{\triangle} = \dfrac{3R^2\sqrt3}{4}[/tex]
2)
[tex]\it \ell_4 = R\sqrt2
\\\;\\ \\\;\\
a_4 = \dfrac{R\sqrt2}{2}
\\\;\\ \\\;\\
\mathcal{A}_{\Box} = 2R^2[/tex]
3)
[tex]\it \ell_6 = R \\\;\\ \\\;\\ a_6= \dfrac{R\sqrt3}{2} \\\;\\ \\\;\\ \mathcal{A} = 6\dfrac{R^2\sqrt3}{4}[/tex]
