SOLUTION
Given the question in the image, the following are the solution steps to answer the question.
STEP 1: Write the given information

STEP 2: Label the two equations

STEP 3: Solve for the missing values
Isolate l in equation 1

Substitute 14-b for l in equation 2

Solve the equation quadratically

Substitute the values into equation 3,

Hence, the dimensions of the pen is given as:
