Question

Find the missing angle or side measure. Provide clear justification for you answers.

Answer 1

Answer:

m∠ D = 110°.

Justification is below.

Step-by-step explanation:

Consider  quadrilateral CDEF as a parallelogram,

Opposite sides of a parallelogram are parallel

∴ DE || CF

If two lines are parallel then the interior angles SUM is 180°

Angle C and Angle D are interior angles.

∴ m ∠C + m∠ D = 180°

Here

m ∠C = 70°      {Given}

on substituting the above value we get

∴ 70 + m∠ D = 180°

∴  m∠ D = 180 - 70

∴  m∠ D = 110°

∴  m∠ D = 110° which is the required answer.