Agriculture Mechanics I

 Linear ◦ Comes from the word line.  Linear Measure ◦ The measurement of lines ◦ A line is the distance between two points. ◦ It is one-dimensional (having length but no width or thickness). ◦ The lines to be measured can be curved, irregular, or straight.

 Perimeter- is the distance around the outside of an area or an object.  For Example, the boundaries of Tulare High School form its perimeter.

 Rectangle- a four sided plane figure with four right angles. ◦ Plane refers to the figure as being two-dimensional (having length and width). ◦ All four sides are not equal. L W

 There is a long and a short method ◦ Long method- add up the lengths of all sides.  P = L + W + L + W ◦ Short method- uses a formula  P = 2L + 2W (2 x length + 2 x width)  Example: ◦ L = 10 ◦ W = 5 ◦ P = 2(10) + 2(5) ◦ P =

 Square- is a plane figure with four equal sides and four right angles.  The formula for finding the perimeter of a square is P = 4 s ◦ The letter “s” stands for the length of one side.  Example: Find the perimeter of a hog pen whose sides are 15 feet. ◦ P = 4 s ◦ P = 4 (15) ◦ P = 60 feet 15’

 Circle- a closed plane curve, every point of which is equally distant from a center point.  The circumference is the perimeter around the circle.  The diameter is the distance across the circle, through the center.  The radius is half of the diameter (from the center to the circle line).

Diameter Radius Circumference

 The formulas used for finding the circumference, diameter, and radius are derived from the relationship that exists between any circle’s circumference and diameter. ◦ This relationship is referred to as the RATIO of the circumference to the diameter.  Circumference/Diameter = 3.14 (rounded off) ◦ The number 3.14 has been named with the Greek letter π (pi) ◦ C / d = π

 To find a circle’s circumference, the following formulas can be used: ◦ C = π x diameter or C=πd ◦ C = 2 x π x radius or C=2πr  Example: Find the circumference of a grain silo when the diameter is 25’. 25 ’ d = 25’ π = 3.14 C = ? C = π x d C = 3.14 x 25 C = 78.5’

 To find a circle’s diameter, the following formulas can be used: ◦ d = C / π ◦ d = 2r  Example: Find the diameter of a stock tank when the circumference is 30’. ? 30 ’ C = 30 π = 3.14 d = ? d = C / π d = 30 / 3.14 d = 9.55’