Trigonometry Flashcards
(26 cards)
SOH
Sine = opposite / hypotenuse
CAH
Cosine = adjacent / hypotenuse
TOA
Tangent = opposite / adjacent
bearings must always use
three digits - 045, 278, 002
Bearings are measured
clockwise from north
Bearings - “from” is
where you put the protractor
Angle of elevation
The angle between the line of sight and horizontal, going up
Angle of depression
The angle between the line of sight and horizontal, going down
0 to 90
All
90 to 180
Sine
180 to 270
Tangent
270 to 360
Cosine
I
a
II
180 - a
III
180 + a
IV
360 - a
Sine rule side
a b c
———— = ———— = ————
sin ( A ) sin ( B ) sin ( C )
Sine rule angle
sin ( A ) sin ( B ) sin ( C )
———— = ———— = ————
a b c
Cosine rule A
a^2 = b^2 + c^2 - 2 x b x c x cos ( A )
Cosine rule B
cos ( A ) = b^2 + c^2 - a^2
———————–
2 x b x c
Area rule
A = 1/2 a x b x sin ( c )
Sine rule side uses…
2 angles and 1 excluded side
Sine rule angle uses…
2 sides and 1 excluded angle
Cosine rule A uses…
2 sides and 1 included angle
