Answer:
Perimeter = 54
Step-by-step explanation:
Since AC = RP, then the following also applies:
AB = RB
CB = PB
So, in order to determine this, you first need to find a common ratio in order to find the missing side of PB which you need for the perimeter.
To determine the ratio you do the following:
AB = 21 (14 + 7)
RB = 7
21: 7 = 3: 1
This means in finding a smaller side you can divide by the value 3 to find it.
It also means that side CP is 2/3 of the value of CB which means that we need 1/3 of the value left in order to determine PB:
CP = 10 = 2/3, which means 1/3 is 5, so
PB = 5
Therefore: CB = 15
Perimeter = CB + AC + AB
15 + 21 + 18 = 54