Central angle CBA is a right angle, so it is 90 degrees. This means the arc measure from A to C, following the shortest path on the curve, is 90 degrees. This is minor arc CA. A minor arc is one that is less than 180 degrees in measure.
We want to find the measure of minor arc DE. This is the last piece of the puzzle, so to speak, that forms the entire arc ACD. This arc is 180 degrees because AD is a diameter.
So,
(minor arc DE) + (minor arc EC) + (minor arc CA) = arc ACD
x + 61 + 90 = 180
x + 151 = 180
x + 151 - 151 = 180 - 151 .... subtract 151 from both sides
x = 29
Minor arc DE is 29 degrees.
Check out the attached image below if you're still stuck. Hopefully the image clears any confusion you may have.
Why?
The first thing we need to do is find the area of the triangle, we can to that by subtracting the area of ABCD from ACBE, then, we can use the formulas to calculate the area for both triangle and rectangle to find "f" and "g".
Calculating we have:
Now, we can calculate "f" by using the formula to calculate the area of the triangle:
Now, finding "g" by using the formula to calculate the area of the rectangle, we have:
Hence, we have that:
Have a nice day!