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Analytic Geometry2D

Solid Geometry - Theory & Concepts - Analytic Geometry Plane Three Points3 D

Three-dimensional coordinate systems, distance, direction cosines, equations of lines and planes in space.

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Plane Defined by Three Points

x₁2.0
y₁1.0
z₁3.0
x₂-1.0
y₂3.0
z₂1.0
x₃1.0
y₃-2.0
z₃-1.0
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1. Direction Vectors
v=P1P2=3.0,2.0,2.0\vec{v} = \overrightarrow{P_1P_2} = \langle -3.0, 2.0, -2.0 \ranglew=P1P3=1.0,3.0,4.0\vec{w} = \overrightarrow{P_1P_3} = \langle -1.0, -3.0, -4.0 \rangle
2. Normal Vector
n=v×w=A,B,C\vec{n} = \vec{v} \times \vec{w} = \langle A, B, C \ranglen=14.0,10.0,11.0\vec{n} = \langle -14.0, -10.0, 11.0 \rangle
3. Plane Equation
A(xx1)+B(yy1)+C(zz1)=0A(x - x_1) + B(y - y_1) + C(z - z_1) = 0
gives:
(14.0)x+(10.0)y+(11.0)z+(5.0)=0(-14.0)x + (-10.0)y + (11.0)z + (5.0) = 0