SOLUTION
Given the question in the image, the following are the solution steps to answer the question.
STEP 1: Explain the formula to use
Using the cosine rule which states that:

STEP 2: Write the given sides

STEP 3: Find the value of z

Hence, the indicated length is 4.0
Answer:
94.248 feet
1,131.0 inches
94′ 3″ feet and inches
28.727 meters
2,872.7 centimeters
Step-by-step explanation:
Perimeter is the distance around an object / shape. Area is the amount of space within a 2 dimensional surface. For example the perimeter of a square would be the lengths of each side added together while the area would be how much space inside of it that it occupies. Area is measured in units squared, while perimeter is left in just units. In other words if the unit ( measurements ) are conducted in cm, then the area would be put in cm^2. The perimeter would just remain in cm.
(6 + 5x)(7x + 3) = 42x + 18 + 35x^2 + 15x = 35x^2 + 57x + 18