Respuesta :

to form a linear pair means that when added, they equal 180 degrees.
but if they have equal measures....180/2 = 90...then they would both equal 90 degrees.....and 90 degrees is a right angle. 
So ABC and CBD are both right angles

Answer:

Right angle

Step-by-step explanation:

When two lines intersect, a linear pair is formed, two angles being linear pair means the sum of those two angles is 180°.

Now if ∠ABC and ∠CBD for a linear pair,

∴∠ABC + ∠CBD = 180°

also given that ∠ABC and ∠CBD are of equal measure

∴ ∠ABC + ∠ABC = 180°

⇒ ∠ABC = 90° = ∠CBD

∴ ∠ABC is right angle