Mathematics Question and Solution
Let the three equal lengths of the quadrilateral be 1 unit each.
Therefore;
a² = 1²+1²-2cos100
a = 1.5320888862 units.
a is BD.
b = 60-½(180-100)
b = 60-40
b = 20°
b is angle ABD.
c² = 1²+1.5320888862²-2*1.5320888862cos20
c = 0.6840402866 units.
c is AD.
Therefore, the required angle, angle BAD (?) is;
Let it be e.
(0.6840402866/sin20) = (1.5320888862/sind)
d = 50°
It implies;
e = 180-d
e = 130°
Again, e is the required angle, angle BAD.
