SOLUTION
Given the question in the image, the following are the solution steps to answer the question.
STEP 1: Write the formula for area of a sector
![Areaofsector=(\theta)/(360)*\pi r^2](https://img.qammunity.org/2023/formulas/mathematics/college/q4zwf0g7ixthn5fk26ybesdbgb7g4dro31.png)
STEP 2: Write the given measures
![\begin{gathered} For\text{ Sector }COD \\ \theta=90\degree \\ radius(r)=? \\ Area\text{ }of\text{ }sector=50.24 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/4gt3gye86wzq4qjei13vz013t9p77umpsv.png)
STEP 3: substitute the values in the formula in step 1
![50.24=(90)/(360)*3.14* r^2](https://img.qammunity.org/2023/formulas/mathematics/college/4q1bwmhyznplo6gx9el75btlnjdxxey3h9.png)
Solve for radius(r)
![\begin{gathered} 50.24=(90)/(360)*3.14r^(2) \\ 50.24=(282.6r^2)/(360) \\ \\ Cross\text{ Multiply} \\ 50.24*360=282.6r^2 \\ r^2=(18086.4)/(282.6) \\ r^2=64 \\ r=√(64)=8\text{ unit} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/xo1o5nc3840zx2nnmhtrgf6qmnooeltnry.png)
Therefore, the radius of the circle is 8 units
STEP 4: Calculate the measure of arc AB
![length\text{ }of\text{ }an\text{ }arc=(\theta)/(360)*2\pi r](https://img.qammunity.org/2023/formulas/mathematics/college/dpu79sqa9zy51576s1huooetkjyuxbon61.png)
STEP 5: Write the known values
![\begin{gathered} \theta=30\degree \\ r=8 \\ \pi=3.14 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/v42dl7mkmnod4m9g403xe8ecd1emmo5rw7.png)
STEP 6: calculate the length of the arc
By substitution in to the formula in step 4, we have:
![\begin{gathered} (30)/(360)*2*3.14*8=(1507.2)/(360)=4.186666667 \\ length\approx4.2units \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/hwcsjkvxy6vwyizajphm3ucyo58lkz3fp6.png)
Hence, the measure of arc AB is approximately 4.2 units