What is the beam angle of LED strip?

The beam angle of LED strip is the angle across the cone of LED from one beam edge to the opposite beam edge. The beam edge is the cone-shaped surface where the beam intensity is 50% of what it is at the center of the beam.
 
A LED strip light has a beam angle of around 120 degrees. A LED spot light has a beam spread of less than 21 degrees. If you compare a LED strip light and LED spot with the same light elements (and lumen output,) the LED strip has a lower “brightness,” as defined by Center Beam Candle Power (luminance) because the LED strip is spreading the light over a larger cone.

Edit: Staff of Shenzhen Masterlite (MTL) Co., Ltd