$$\frac{1}{2}\ \cdot\ b\ \cdot\ h$$  

$$\frac{1}{2}\ \cdot\ h\ \cdot\ \left(b1\ +\ b2\right)$$  

$$b\ \cdot\ h$$  

$$l\ \cdot\ w$$  

A = l•w

A = s + s + s + s

A = π r²

A= l ⋅w⋅h

C=πr²

C=2πr

C=2π

C=πd

midpoint

slope

distance

average

$$d\ =\ \sqrt{\left(y_{1\ }-\ y_2\right)^2\ -\left(x_{2\ }-\ x_1\right)^2}\$$

$$d\ =\ \sqrt{\left(x_{2\ }-\ x_1\right)^2\ +\ \left(y_{2_{\ }}-\ y_1\ \right)^2}$$

$$d\ =\ \sqrt{\left(y_{1\ }-\ y_2\right)^2\ +\ \left(x_{2\ }-\ x_1\right)^2}$$

d = $$\sqrt{\left(x\right)^2-\ \left(y\right)^2}$$

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