Mobile terminal including touch screen supporting multi-touch input and method of controlling the same

1. A method of controlling a mobile terminal including a touch screen supporting a multi-touch input, the method comprising:

determining a number of one or more points inputted as a first touch input on the touch screen;

when the number is 3, determining the first touch input as a three-point input;

determining a size of a largest internal angle of a triangle generated by connecting points of the three-point input on the touch screen;

displaying one of a linear tool and a circular tool based on a size of the largest internal angle of the triangle;

receiving a second touch input;

generating a line corresponding to the second touch input by interworking with one of the linear tool and the circular tool; and

displaying the generated line on the touch screen.

2. The method of claim 1 , wherein displaying one of the linear tool and the circular tool comprises:

determining whether the largest internal angle of the triangle is greater than or equal to a pre-stored reference angle;

displaying the linear tool based on coordinates of the points when the largest internal angle of the triangle is greater than or equal to the pre-stored reference angle; and

displaying the circular tool based on coordinates of the points when the largest internal angle of the triangle is less than the pre-stored reference angle.

3. The method of claim 2 , wherein, when the linear tool is displayed, receiving the second touch input comprises receiving a user input of drawing a line in a position close to the linear tool.

4. The method of claim 3 , wherein, when the linear tool is displayed, generating the line comprises:

determining whether the line has a length that is greater than or equal to a pre-stored length, and

generating the line when the length is greater than or equal to the pre-stored length.

5. The method of claim 2 , wherein, when the circular tool is displayed, receiving the second touch input comprises receiving a user input of drawing an arc in a position close to the circular tool.

6. The method of claim 5 , wherein, when the circular tool is displayed, generating the line comprises:

determining whether the arc has an angle that is greater than or equal to a pre-stored angle; and

generating the arc when the angle is greater than or equal to the pre-stored angle.

7. The method of claim 1 , wherein displaying the generated line comprises removing the one of the linear tool and the circular tool from the touch screen.

8. The method of claim 1 , further comprising:

when the number is 4, determine the first touch input as a four-point input;

displaying a figure tool corresponding to the four-point input;

receiving a third touch input selecting one of a plurality of figures included in the figure tool; and

displaying the selected one of the plurality of figures on the touch screen.

9. The method of claim 8 , further comprising:

receiving a fourth touch input; and

rearranging the plurality of figures in the figure tool in response to the fourth touch input.

10. The method of claim 8 , further comprising receiving a fourth touch input tracing the selected one of the plurality of figures included in the figure tool, wherein the selected on of the plurality of figures is displayed based on the fourth touch input.

11. A mobile terminal comprising:

a touch screen configured to receive a first touch input, and a second touch input; and

a controller configured to:

determine a number of one or more points inputted as a first touch input on the touch screen;

when the number is 3, determine the first touch input as a three-point input;

determine a size of a largest internal angle of a triangle generated by connecting points of the three-point input on the touch screen,

control the touch screen to display one of a linear tool and a circular tool based on a size of the largest internal angle of the triangle,

generate a line corresponding to the second touch input by interworking with the one of the linear tool and the circular tool, and

control the touch screen to display the generated line.

12. The mobile terminal of claim 11 , wherein, in controlling the touch screen to display one of the linear tool and the circular tool, the controller determines whether the largest internal angle of the triangle is greater than or equal to a pre-stored reference angle, displays the linear tool based on coordinates of the points when the largest internal angle of the triangle is greater than or equal to the pre-stored reference angle, and displays the circular tool based on coordinates of the points when the largest internal angle of the triangle is less than the pre-stored reference angle.

13. The mobile terminal of claim 12 , wherein, when the linear tool is displayed, the second touch input is a user input of drawing a line in a position close to the linear tool.

14. The mobile terminal of claim 13 , wherein, when the linear tool is displayed, the controller generates the line by determining whether the line has a length that is greater than or equal to a pre-stored length, and generating the line when the length is greater than or equal to the pre-stored length.

15. The mobile terminal of claim 12 , wherein, when the circular tool is displayed, the second touch input is a user input of drawing an arc having a pre-stored angle or larger in a position close to the circular tool.

16. The mobile terminal of claim 15 , wherein, when the circular tool is displayed, the controller generates the line by determining whether the arc has an angle that is greater than or equal to a pre-stored angle, and generating the arc when the angle is greater than or equal to the pre-stored angle.

17. The mobile terminal of claim 11 , wherein the controller removes the one of the linear tool and the circular tool from the touch screen when the controller displays the generated line on the touch screen.

18. The mobile terminal of claim 11 , wherein

when the number is 4, the controller determines the first touch input as a four-point input, and controls the touch screen to display a figure tool corresponding to the four-point input

when a third touch input selecting one of a plurality of figures included in the figure tool is received, the controller controls the touch screen to display the one of the plurality of figures on the touch screen.

19. The mobile terminal of claim 18 , wherein the touch screen receives a fourth touch input, and the controller rearranges the plurality of figures in the figure tool in response to the fourth touch input.

20. The mobile terminal of claim 18 , wherein the touch screen receives a fourth touch input tracing the selected one of the plurality of figures included in the figure tool, and the controller displays the selected one of the plurality of figures based on the third touch input.