# Geometry 3.1-3.6

## 32 terms · I hate this class... too many postulates!

### Two Parallel lines

Do not intersect and are coplanar

### Two skew lines

do not intersect and are not coplanar

### Transversal

line that intersects two or more coplanar lines at different points

### Corresponding Angles

Corresponding positions and congruent

### Alternate interior angles

They lie between 2 lines and on opposite sides and Congruent

### Alternate Exterior

They lie outside the 2 lines and are on opposite sides and congruent

### Consecutive interior

They lie between two lines and on the same side and supplementary

### Transitive Property of Parallel Lines

if p≅q & q≅r, then p≅q

### Parallel Postulate

If there is a line and point not on the line, then there is exactly 1 line through the point parallel to the given line

### Perpendicular Postulate

If there is a line and point not on the line then there is exactly 1 line through the point perpendicular to the given line

### Corresponding Angles Postulate

If 2 parallel lines are cut by a transversal, then the pairs of corresponding angles are congruent

### Alt. Interior Angles Theorem

If 2 parallel lines are cut by a transversal, then the pairs of alternate interior angles are congruent

### Alt. Exterior Angles Theorem

If 2 parallel lines are cut by a transversal, then the pairs of alternate exterior angles are congruent

### Consecutive Interior Angles Theorem

If two parallel lines are cut by a transversal, then the pairs of consecutive interior angles are supplementary

### Corresponding Angles Converse

If two lines are cut by a transversal so the corresponding angles are congruent, then the lines are parallel

### Alt. Interior Angles Converse

If two lines are cut by a transversal so the alternate interrior angles are congruent, then the lines are parallel

### Alt. Exterior Angles Converse

If two lines are cut by a transversal so the alternate exterior angles are congruent, then the lines are parallel

### Consecutive Interior Angles Converse

If two lines are cut by a transversal so the consecutive interior angles are supplementary, then the lines are parallel

### Transitive Property of Parallel Lines

If two lines are parallel to the same line, then they are parallel to each other

y₂-y₁/x₂ -x₁

mx +b=y

Ax + By= C

y-y₁=m(x-x₁)

### Steep slope reminder

The absolute value of the slope, pick the higher one

### Shortest distance between any 2 parallel lines

lies a ⊥ distance

### If 2 lines intersect to form a linear pair of ≅ angles

then the lines are ⊥ (linear pair)

### If 2 lines are ⊥

then they intersect to form 4 right angles

### If 2 sides of 2 acute adjacent angles are ⊥

then the angles are complementary

### Perpendicular Transversal Theorem

If a transversal is ⊥ to one of 2 parallel lines, then it is ⊥ to the second line

### Lines ⊥ to a Transversal Theorem

In a plane, if 2 lines are ⊥ to the same line then the lines are parallel to one another

### Slope of Parallel lines

They have the same slope

### Slope of ⊥ (perpendicular) lines

product of Slopes have to equal -1, reciprocal and reverse sign