# Triangle

## Online Tutoring Is The Easiest, Most Cost-Effective Way For Students To Get The Help They Need Whenever They Need It.

#### SIGN UP FOR A FREE TRIAL

On a plane figure when three lines  intersect each other at their last end is called a triangle. The end place where lines intersect to other lines, makes a corner. These corners makes an angle. In a triangle there are only three corners and three angles. The sum of all the three angles in a triangle is 180°. There are 3 types of triangles:

 1) Acute angled triangle All the angles in a acute angled triangle are <90°. 2) Right angled triangle One of the angles in a right angled triangle is 90° 3) Obtuse angled triangle One of the angles in an obtuse angled triangle is >90°
Example 1: Two angles of a triangle measures 59° and 85°. Find the remaining angle?
 Answer: Sum of all the angles in a triangle is 180°. 59° + 85° + x = 180° 144° + x = 180° x = 36°
Hence the third angle is 36°.
Example 2: The three angles of a triangle measure (3x) °, (4x – 8) °, (3x – 2) °. Find x and all the three angles.
 Answer: 3x + 4x – 8 + 3x – 2 = 180 10x – 10 = 180 10x = 190 x = 19°
First angle = 3x = 3(19) = 57°
 Second angle = 4x – 8 = 4(19) – 8 = 76 – 8 = 68°
 Third angle = 3x – 2 = 3(19) – 2 = 57 – 2 = 55°