Answer and Step-by-step explanation:
We want to find the measure of angle ABD (∠ABD).
We can tell by looking at this triangle that the array BD creates complementary angles (two angles who's sum equals 90°). ∠CBD is given to us, and we want to find ∠ABD. By knowing that these two angles will add up to 90°, we can create a formula to solve for ∠ABD.
90° = ∠ABD + ∠CBD
Plug in the angle for ∠CBD.
90° = ∠ABD + 45°.
Subtract 45° from both sides of the equation.
90° - 45° = ∠ABD + 45° - 45°
45° = ∠ABD
So, angle ∠ABD is 45°.
Have a great day!