Answer:
16.6
Step-by-step explanation:
The rectangle has an area of 105. It's width is 7.
1: Find the length
=length
= 15
Length=15
2: Pythagorean theorem

+
49+225=
275=
= 
16.55≈c
Rounded to nearest tenth
16.6
Choice A is correct
BC=DC
the two triangles share one angel C
the two triangles each have a right angle
so they are congruent according to Angle-Side_Side Theorem
Answer: The second answer.
Step-by-step explanation: