Find time duration between two pulse of same signal

i want to find time duration between two pulse of same signal. That’s mean time duration between falling edge of first pulse and rising edge of second signal. Here, i’m using Arduino Uno board. Here, Image attached show my two pulse of same signal. i want to find time t. I want some logic or arduino code.

Check what you could do with pulsein()

(Find a good way to wait for the pin to go HIGH then use the function with LOW as a parameter)

i want to find time duration between two pulse of same signal. That's mean time duration between falling edge of first pulse and rising edge of second signal.

How difficult is it to detect a change from LOW to HIGH? Not at all difficult, as the state change detection example shows. How difficult is to record when that happens? Not at all difficult, since there are millis() and micros() functions.

How difficult is it to subtract then from now, when the other edge happens? Really, could anything be simpler?