Finding True North

In New Zealand, at 12:30pm in winter months and 1:30pm during daylight savings time on a sunny day the line along the shadow cast by a vertical surface such as a door jamb or the edge of a building will be close enough. Extend this line using string or similar, as necessary.

Formulae for Basic Trig for Solar Panel Mounts

Always use a right angle triangle when solving problems relating to structures such as roofs and frames. Use our Calculator to get the results quickly and easily.

Referring to the triangle (left)... Side "A" is "Opposite" the angle "X" we have or that we intend to solve for. Side "B" is "Adjacent" to the angle "X" we have or that we intend to solve for. Side "C" is the "Hypotenuse". It is the longest side and opposite the right angle.

Sine	Cosine	Tangent
If you have length of any two sides, calculate the Angle X° using the formulae below
SIN(X) = O/H	COS(X) = A/H	TAN(X) = O/A
If you have the Angle X° and the length of one side, calculate the length of any other side using the formulae below
H = SIN(X) / O	H = COS(X) / A	A = TAN(X) / O
O = SIN(X) * H	A = COS(X) * H	O = TAN(X) * A