Which angle is an inscribed angle 1 2 3 4

∠1

Step-by-step explanation:

we know that

An inscribed angle in a circle is formed by two chords that have a common end point on the circle

The measure of the inscribed angle is half of measure of the intercepted arc

In this problem

∠1 is an inscribed angle

∠2 is an outer angle

∠3 is an interior angle

∠4 is an semi-inscribed angle ( angle formed by a chord and a tangent)

0.02

step-by-step explanation:

time of 9 192 631 770 periods of the radiation corresponding to the transition between the 2 hyperfine levels of the ground state of the caesium 133 atom at 0 k (but other seconds are sometimes used in astronomy)