How can you use Blockly to create a program that triggers an alert when the distance measured by an ultrasonic sensor exceeds a certain threshold?

You can use Blockly to create a program that reads the distance measured by the ultrasonic sensor and triggers an alert when the distance exceeds a specific threshold. By using if-else blocks, you can check if the measured distance is greater than the threshold and trigger the alert using appropriate blocks such as sound or LED control blocks.