**Lines and Angles :**

In this section, we are going to study about relationship between lines, parallel postulate, perpendicular postulate and angles formed by transversals.

Two lines are parallel lines, if they are coplanar and do not intersect. Lines that do not intersect and are not coplanar are called skew lines. Similarly, two planes that do not intersect are called parallel planes.

To write "AB" is parallel to "CD", we write AB||CD. Triangles like those AB and CD are used on diagrams to indicate that lines are parallel. Segments and rays are parallel if they lie on parallel lines.

For example, AB||CD.

**Parallel Postulate : **

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

The diagram given below illustrates this.

**Perpendicular Postulate : **

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

The diagram given below illustrates this.

A transversal is a line that intersects two or more coplanar lines at different points. For instance, in the diagrams below, line "t" is transversal. The angles formed by two lines and a transversal are given special names.

**Corresponding Angles : **

Two angles are corresponding angles, if they occupy corresponding positions.

For example, in the diagram given below, angles **1** and **5** are corresponding angles.

**Alternate Exterior Angles : **

Two angles are alternate exterior angles, if they lie outside the two lines on opposite sides of the transversal.

For example, in the diagram given below, angles **1 **and **8 **are alternate exterior angles.

**Alternate Interior Angles : **

Two angles are alternate interior angles, if they lie between the two lines on opposite sides of the transversal.

For example, in the diagram given below, angles **3 **and **6 **are alternate interior angles.

**Consecutive Interior Angles :**

Two angles are consecutive interior angles, if they lie between the two lines on the same side of the transversal.

Consecutive interior angles are also called same side interior angles.

For example, in the diagram given below, angles **3 **and **5 **are consecutive interior angles.

After having gone through the stuff given above, we hope that the students would have understood "Lines and angles".

Apart from the stuff given above, if you want to know more about "Lines and angles", please click here

Apart from the stuff given in this section, if you need any other stuff in math, please use our google custom search here.

HTML Comment Box is loading comments...

**WORD PROBLEMS**

**HCF and LCM word problems**

**Word problems on simple equations **

**Word problems on linear equations **

**Word problems on quadratic equations**

**Area and perimeter word problems**

**Word problems on direct variation and inverse variation **

**Word problems on comparing rates**

**Converting customary units word problems **

**Converting metric units word problems**

**Word problems on simple interest**

**Word problems on compound interest**

**Word problems on types of angles **

**Complementary and supplementary angles word problems**

**Markup and markdown word problems **

**Word problems on mixed fractrions**

**One step equation word problems**

**Linear inequalities word problems**

**Ratio and proportion word problems**

**Word problems on sets and venn diagrams**

**Pythagorean theorem word problems**

**Percent of a number word problems**

**Word problems on constant speed**

**Word problems on average speed **

**Word problems on sum of the angles of a triangle is 180 degree**

**OTHER TOPICS **

**Time, speed and distance shortcuts**

**Ratio and proportion shortcuts**

**Domain and range of rational functions**

**Domain and range of rational functions with holes**

**Graphing rational functions with holes**

**Converting repeating decimals in to fractions**

**Decimal representation of rational numbers**

**Finding square root using long division**

**L.C.M method to solve time and work problems**

**Translating the word problems in to algebraic expressions**

**Remainder when 2 power 256 is divided by 17**

**Remainder when 17 power 23 is divided by 16**

**Sum of all three digit numbers divisible by 6**

**Sum of all three digit numbers divisible by 7**

**Sum of all three digit numbers divisible by 8**

**Sum of all three digit numbers formed using 1, 3, 4**

**Sum of all three four digit numbers formed with non zero digits**