# Which tool is very suitable to draw geometry picture for mathematics?

Such as :

What is the most convenient tool to draw pictures like this?

I want to find a tool which will automatically detect what I need.

For example, when I need to draw a line vertically, it can detect that and stay vertically for a while to let me understand in that direction is a vertically line.

Thank you~

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nearly all drawing tools allow you to fix a line to the vertical, just hold ctrl as your draw it. – Sirex Dec 19 '11 at 7:49

You would use a mathematical application like Geogebra, you can directly introduce the equation of the Parabola or create it using its focus (F) and its linear directrix (H). Using the relation: "any point P on the parabola will be equidistant from both the focus and the linear directrix".

You can use another mathematical applications, but Geogebra is the most intuitive and you can introduce an equation to be drawed or draw directly in the cartesian plane. And you can export your drawings as an image or an interactive applet.

In Geogebra is possible to create another geometrical entities as lines, points, circles, etc. and create another ones using intersections, angle and linear segments bisections, etc.

I am a math teacher and a programmer who teaches my students Geogebra as a tool for learning Mathematics.

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If I have any question about Geogebra,where can I ask? For example, I want to draw symbol like '|_' (right angle), I have no idea to draw it. Thank you~ – sam Dec 20 '11 at 13:53
If you have any question, you can go to the Geogebra forums. To draw the right angle, go to the "angle" button, click and select a point in the H line, the point vertex of the angle and a point in the perpendicular line. – Kijote Dec 28 '11 at 14:33

There are many tools. For mathematical diagrams, I would consider at least:

But I am not a mathematician.

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