Arithmatical - Heights and Distance

DIRECTIONS : Important Facts and Formulae
1.
Trigonometry:
In a right angled Δ OAB, where BOA = θ,
i . 
 sin θ = Perpendicular / Hypotenuse = AB/OB
ii .
 cos θ = Base / Hypotenuse = OA/OB
iii .
 tan θ = Perpendicular / Base = AB/OA
iv .
 cosec θ = 1/sin θ = OB/AB
v .
 sec θ = 1/cos θ = OB/OA
vi .
 cot θ = 1/tan θ = OA/AB

1.
Trigonometrical Identities:
i . 
 sin2 θ + cos2θ = 1
ii . 
 1 + tan2 θ = sec2 θ
iii . 
 1 + cot2 θ = cosec2 θ