Consider rectangle ABCD If mADF60 then what is the mFDC a 60
Consider rectangle ABCD. If mADF=60°, then what is the mFDC?
a) 60°
b) 30°
c) 90°
d) 120°
e) 45°
f) None of the above
Solution
Given figure ABCD is a rectangle.
 Looking into the properties of rectangle,
 1) All the angles in a rectangle are right angles i.e. equal to 90 degrees.
 2) Opposite sides are parallel and equal.
By the first property stated above,
 m(D) = 90 degrees
 Angle D can be written as given in the following
 m(D) = m(ADF) + m(FDC) = 90
 Given m(ADF) = 60
 Therefore, 60 + m(FDC) = 90
 m(FDC) = 30 degress.
 
 Hence option B) 30 is the required answer.

