Adherence to right angles is a must when building walls. Drawing a right angle on paper is not too complicated, for example using a triangle with a line. There are also masonry angles, but due to the dimensions they are not always accurate enough.

Every good bricklayer can draw a right angle with the help of an ordinary string. He will help himself with the Pythagorean theorem! Every triangle has a right angle against its longest side, the lengths of which are in the so-called Pythagorean ratio. Measuring a length is much easier than measuring an angle.

An angle is a part of a plane bounded by two half-lines with a common beginning.

Acute angle

Right angle

Straight angle

Obtuse angle

Hollow angle

Types of triangles according to the size of internal angles

Sharp – all interior angles are sharp

V – is as an interior point

Rectangular – just one inner angle is a right

V – coincides with the vertex of the right angle

Obtuse – just one inner angle is obtuse

V – has as an outer point