volume
$$ V = \frac{1}{3} L_a \cdot t $$
luas permukaan
$$ L = L_a + L_{s} $$
luas alas
$$
\begin{aligned}
&L_a = \frac{1}{4} n a^2 \cot\frac{180^\circ}{n} \\ \\
& n = 3 \ \Rightarrow \ L_a = \frac{\sqrt{3}}{4} a^2 \\ \\
& n = 4 \ \Rightarrow \ L_a = a^2
\end{aligned}
$$
luas selimut
$$ L_{s} = \frac{n a t_a}{2} $$
rusuk tegak
$$
\begin{aligned}
s &= \frac{t}{\sin\alpha_1} \\ \\
s &= \sqrt{t^2 + R^2} \\ \\
s &= \sqrt{t_a^2 + \left(\frac{a}{2}\right)^2}
\end{aligned}
$$
tinggi sisi tegak (apotema)
$$
\begin{aligned}
t_a &= \frac{t}{\sin\alpha_2} \\ \\
t_a &= \sqrt{t^2 + r^2} \\ \\
t_a &= \sqrt{s^2 - \left(\frac{a}{2}\right)^2}
\end{aligned}
$$
lingkaran luar (jari-jari)
$$
\begin{aligned}
&R = \frac{a}{2\cdot\sin\frac{180^\circ}{n}} \\ \\
& n = 3 \ \Rightarrow \ R = \frac{a}{\sqrt{3}} \\ \\
& n = 4 \ \Rightarrow \ R = \frac{a}{\sqrt{2}}
\end{aligned}
$$
lingkaran dalam (jari-jari)
$$
\begin{aligned}
&r = \frac{a}{2\cdot\tan\frac{180^\circ}{n}} \\ \\
& n = 3 \ \Rightarrow \ r = \frac{\sqrt{3}}{6}a \\ \\
& n = 4 \ \Rightarrow \ r = \frac{a}{2}
\end{aligned}
$$
