Viewing in Doors & Windows. Many people use a screwdriver to remove a hinge pin when taking off a door. They simply place the tip up under the head of the pin and then tap on the end with a hammer.
Complementary angles are two angles whose measures add up to 90 degrees. You can think of them as two puzzle pieces that form one 90 degree angle when they are put together. When talking about complementary angles, it's important to remember that they're always in a pair.
Math Open Reference. Definition: A line which cuts a line segment into two equal parts at 90Â°. Try this Drag one of the orange dots at A or B and note the the line AB always divides the segment PQ into two equal parts. When it is exactly at right angles to PQ it is called the perpendicular bisector.