__maths__>__Construction / Practical Geometry (basics)__>__Construction of Triangles (Fundamental Shape of Polygons)__### Construction of Triangle(SAL)

In this page, a short and to-the-point overview of constructing triangles with side-angle-latitude is provided.

*click on the content to continue..*

To construct a triangle, "side-angle-altitude" are provided. Which of the following is required to construct the specified triangle?

- a scale to mark the given sides
- a compass to mark angles and sides
- a ruler, a set-square and a protractor to mark side, parallel, and angle
- a ruler, a set-square and a protractor to mark side, parallel, and angle

The answer is "a ruler, a set-square and a protractor to mark side, parallel, and angle"

To construct a triangle `/_\ ABC` with given "side-angle-altitude" `4`cm, `70^@`, and `5`cm. • Construct a line and mark side `bar(AB)` with a compass measuring `6`cm

• measure `70^@` angle and draw a ray from point `A`

• The objective is to draw a parallel at given `5`cm distance. To achieve this, draw a perpendicular bi-sector for `bar(AB)` and from point `D` mark point `E` at `5`cm. Construct a parallel to on `bar(AB)` point `E`

• the parallel and the ray cut at point `C`. Connect the point to point `B` to get `bar(BC)`

`/_\ ABC` is constructed.

**Construction of SAL triangle** : Use a ruler, protractor, a compass, and a set-square to mark side, angle and parallel. Once the vertices are marked, join them to form the triangle.

*slide-show version coming soon*