Question

m∥n, m∠1 = 65°, m∠2 = 60°, and m∠6 = 85°. What is m∠DBC?

Answer 1

Answer:

∠DBC = 40°

Step-by-step explanation:

We are given a figure where we know that the angle m∠1 = 65°, m∠2 = 60° and m∠6 = 85°. With the help of these given measures of the angles, we are to find the measure of the angle m∠DBC.

Since the sum of angles in a triangle is equal to 180 degrees, so:

∠1 + ∠2 + ∠3 = 180

∠3 = 180 - (65 + 60)

∠3 = 55°

Also ∠6 and ∠B are alternate interior angles so if ∠6 = 85° then ∠B is also = 85°.

Now that we know ∠3 and ∠B, we can find ∠DBC:

∠DBC = 180 - (85 + 55)

∠DBC = 40°

Answer 2

Answer:40

Step-by-step explanation:

See angle 1 = 65°

Angle 2 = 60°

We know in a triangle all angle count 180°

So angle 3 = 55°

Now in a straight line all angle count 180°

So angle DBC + angle 3 + remaining angle along the line m will count 180°

Now angle 6 and remaining angle along the line m will be equal as 'm' ?and 'b' are parallel lines and t is intersecting them so it subtend equal angles.

Angle 6 = 85° so remaining angle along the line m is also 85°

We know angle DBC + angle 3 + rem. angle = 180°

Or 55° + 85° + angle DBC = 180°

Therefore, angle DBC = 40°

Hope it helps!!!