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Challenge Question Number 1 for Electrician #1074

Clearly describe what you expect from the students:
The electrician has received training during his/her apprenticeship on how to bend conduit. During the conduit bending training, a review of basic trigonometry was necessary to allow the apprentice a better understanding of the relationships regarding the right triangle. As you can see by the drawing below, the offset placed in the conduit forms a right triangle with the obstruction. The unknown distance between bends is the "hypotenuse" of the triangle. The height of the eight-inch obstruction will form the side opposite. Using the trigonometric function of sine, calculate the distance between bends.

In order to give the teacher some guidance in evaluating the student's project(s); list some tips that may help to assess the student's work:
Since the electrician has the known values of the angle theta and the side opposite the angle, then he/she must determine the hypotenuse by dividing the height of the opposite side by the sine of 30 degrees (the angle of the bends). The sine of a 30 degree angle is .5; therefore, a desired offset height of 8 inches divided by .5 is 16 inches. The electrician will need to place the two bends on the conduit sixteen inches apart.

It becomes apparent why most electricians bend all offsets using 30 degree angles so that the height of the offset is simply multiplied by two in order to obtain the distance between bends.