What is the arc length when θ = 4 pi over 7 and the radius is 5 cm? 20 pi over 7cm 4 pi over 7cm 2 pi over 7cm 24 pi over 7cm

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.

Which geometric principle is used to justify the construction below?

Urgent? will give brainliest to the first correct answer what is the area of the figure?