Final answer:
The area of sector HJK in circle J is approximately 67.03 square units.
Step-by-step explanation:
To find the area of a sector in a circle, you need to use the formula A = (m/360)πr², where A is the area of the sector, m is the measure of the central angle, and r is the radius of the circle.
In this case, the measure of the central angle is 126 degrees, so we can plug that into the formula as (126/360)π(20)².
Simplifying this expression gives us (7/20)π(20)², which is equal to 7π square units. When rounded to the nearest hundredth, the area of sector HJK is approximately 67.03 square units.