Question

identifying angle pair relationships
use the diagram to identify the special angle pairs.
$angle adc$ and $angle bdc$ are
a pair of complementary angles is angles

Explanation:

Step1: Analyze ∠ADC and ∠BDC

∠ADC and ∠BDC share side DC, their non-shared sides form a straight line (ADB), so they sum to $180^\circ$.

Step2: Identify complementary angle pair

Complementary angles sum to $90^\circ$. The orange mark at C indicates ∠ACD and ∠BCD form a right angle, so they are complementary.

Answer:

∠ADC and ∠BDC are supplementary angles
A pair of complementary angles is angles ∠ACD and ∠BCD