RIGHT ANGLE TRIANGLES
The right angle triangle is a very important and useful tool in sheet metal flat pattern development. Triangle rules state that the sum of all three angles in a triangle = 180°. If one angle = 90° then it is called a right angle triangle. If   there   is   at   least   two   known   features   of   a   right   angle triangle than the whole triangle can be solved. TRIGONOMETRY MADE SIMPLE! THREE IMPORTANT BUTTONS ON YOUR CALCULATOR: sin  cos  tan   IF A SIDE & AN ANGLE IS KNOWN SOLVE              FORMULAS (E) D & B A tan D x B  or (B ÷ tan E) (E) D & B C B ÷ cos D  or (B ÷ sin E) (E) D & A B A ÷ tan D  or (A x tan E) (E) D & A C A ÷ sin D  or (A ÷ cos E) (E) D & C A sin D x C  or (cos E x C) (E) D & C B cos D x C  or (sin E x C)  D E 90 - D  E D 90 - E Do the following problems. 1.  If D = 30° and C = 4.024 what is A = _________ 2.  If E = 60° and A = 2.012 what is C = _________ 3.  If D = 30° and C = 4.024 what is B = _________ 4.  If D = 45° and B = 2.500 what is A = _________