Respuesta :

m∠BDC = 1/2(178 - 42)
m∠BDC = 1/2(136)
m∠BDC = 68

answer
68° 

The measure of m∠BDC is 68.

What is arc?

An arc of a circle is any portion of the circumference of a circle. To recall, the circumference of a circle is the perimeter or distance around a circle. Therefore, we can say that the circumference of a circle is the full arc of the circle itself.

Minor And Major Arc:

An arc less than one-half of the whole arc of the circle is called the minor arc of the circle, and an arc greater than one-half of the whole arc is called the major arc of the circle.

Axiom of Equal Arcs: If two arcs subtend equal angles at the centres or centre in equal circles or the same circle, they are equal.

  • In equal circles or the same circle, equal chords cut off equal arcs.
  • In equal circles or the same circle, if two arcs are equal, then their chords are equal.

Given:

mAC 178°, mBC= 42

Now, using

angle= far arc- near arc /2

m∠BDC = 1/2(178 - 42)

m∠BDC = 1/2(136)

m∠BDC = 68

Learn more about arc here:

https://brainly.com/question/18741430

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