Answer:
C
Step-by-step explanation:
Calculate the values of both r and s, that is
= 7 ( multiply both sides by 2 )
5 + r = 14 ( subtract 5 from both sides )
r = 9
and
= 3 ( multiply both sides by 2 )
3 + s = 6 ( subtract 3 from both sides )
s = 3
Hence
=
= 6 → C
Answer:
Step-by-step explanation:
Given: △ABC, D∈AC , m∠BDC=m∠ABC , AD=7, DC=9.
Solution: Let BC=x, From the given figure and the given information, it can be seen that △ABC is similar to ΔBDC by AA rule, thus using the proportionality theorem, we get
⇒
⇒
⇒
⇒BC=12
Now, calculate the similarity scale,
k=
=
Therefore,
⇒
⇒