Angles alternate-intern

Definition:

$\backslash \; text\; \{the\; angles\}\; \backslash \; widehat\; \{xAB\}\; \backslash \; text\; \{and\}\; \backslash \; widehat\; \{ABy\text{'}\}\; \backslash \; mathrm\; \{~sont~situ\; \backslash \; acute\; be:\}$

- Between the 2 lines (xx') and (yy')

- On both sides of the right-hand side (tt')

It is said that they are alternate-intern

Property:

If the lines are parallel, then the angles alternate-intern are equal.

Reciprocally, if two angles alternate-intern are equal, then the lines are parallel.

Example:

On the following figure, the right S has and B is parallel S, S is a unspecified Sécante.

The Angle S $\backslash \; alpha$ and $\backslash \; beta$ are equal.

See too

• Angles alternate-external
• corresponding Angles

Random links:

Petal | Canton of Bellencombre | Ron Hagerthy | P4 Jean Merieux | Rene Audubert | Kappa_de_thêta_de_phi

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