Answer:
BD = 9
AB = 9√2
Step-by-step explanation:
The interior angles of a triangle sum to 180°.
Therefore, if angle BAD in right triangle BAD is 45°, then angle DBA is also 45°. This means that triangle BAD is a 45-45-90 triangle.
What is a 45-45-90 triangle?
A 45-45-90 triangle is a special right triangle in that the measures of its sides are in the proportion x : x : x√2 where:
- x is the side opposite the 45 degree angle (legs).
- x√2 is the side opposite the right angle (hypotenuse).
As triangle BAD is a 45-45-90 triangle, sides BD and AD are the same length. Therefore, given the length of side AD is 9 units, BD = 9.
To find the length of AB (the hypotenuse), simply multiply the length of one of the congruent sides by √2. Therefore, AB = 9√2.