DSE 數學公式 (Maths Formula): Mensuration Formula 求積法公式公式

Mensuration Formula

	Perimeter 周界 (cm / m)	Area 面積 (cm^2 / m^2)
	a + b + c	\frac{1}{2}absin θ Heron’ s formula \sqrt{s(s − a)(s − b)(s − c)} s = \frac{a+b+c}{2}
	a + b + c + d	\frac{(a+b)h}{2}
	4a	2xy
	2πr	πr^2
	2πr × \frac{θ}{360°} + 2r	πr^2 × \frac{θ}{360°}
	Volume 體積 (cm^3 / m^3)	Total surface area 總表面面積 (cm^2 / m^2)
	a^3	6a^2
	blh	2(bh + bl + oh)
	Ah	Base Perimeter × h + 2A
	πr^2h	2πrh + 2πr^2
	\frac{1}{3}πr^2h	πrl + πr^2
	\frac{1}{3}Ah	base area + Other lateral face area 其他側面面積
	\frac{4}{3}πr^3	4πr^2
	\frac{2}{3}πr^3	2πr^2 + πr^2

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→ Similar figures

ratio of side = ratio of side   邊長比例 = 邊長比例

\frac{l_1}{l_2} = \frac{h_1}{h_2}

(ratio of side)^2 = ratio of area   (邊長比例)^2 = 面積比例

(\frac{l_1}{l_2})^2 = \frac{A_1}{A_2}

(ratio of side)^3 = ratio of volume   (邊長比例)^3 = 體積比例

(\frac{l_1}{l_2})^3 = \frac{V_1}{V_2}