2016-17. Triangles: Notable lines

Triangles

• Circumcircle of a triangle and How to construct the circumcircle of a triangle
• Orthocenter of a Triangle

Isosceles triangle

Construction of an isosceles triangle with known unequal side and unequal angle.

I've been looking for an explanation in English, but I've only found it in Spanish.

Right-angled triangle

Construct the right angled triangle with known hypotenuse a and known sum of the sides b and c.

It is possible to draw a right angled triangle knowing the difference between b and c.

And some of your practices:

2016-17. Triangles: Problem solving

There are some typical geometry problems that can be easily solved using ruler (or straightedge) and compass.

Triangles

• Triangle given three sides (SSS)
• Triangle given two sides and included angle (SAS)
• Triangle given two angles and the included side (ASA)
• Circumcircle of a Triangle
• Incenter of a Triangle
• Centroid (Barycenter) of a Triangle
• Orthocenter of a Triangle 

Right triangle

• Right triangle given one leg and hypotenuse (HL)
• Right triangle given each leg (LL)
• Right triangle given one angle and one leg (LA)
• Right triangle given one angle and hypotenuse (HA)

And some of your practices: