A technician often has to sketch or design ductwork and the other parts of an HVAC system. Sometimes you have to sketch the room or building you are working with. This means working with lines, angles ...

“Why are there 360 degrees in a circle?” A regular reader recently asked me that question. My first response was to say “Because Miss Helland told me so.” Miss Helland was my high school teacher for ...

Learn the essential definitions of the parts of a circle. A secant line to a circle is a line that crosses exactly two points on the circle while a tangent line to a circle is a line that touches ...

Revise the different types of angles and rules for calculating angles. This guide includes interactive activities and a quiz. NEW: Angles in parallel lines Revise alternate, correspondent or ...

Arc length is a fraction of circumference. Area of a sector is a fractions of the area of a circle. Both can be calculated using the angle at the centre and the diameter or radius. Practice circle ...