Question

What is angular strain here.?

Answer 1

increase in potential energy of a molecule due to deviation of bond angles from ideal values( I am honest and therefore inform that I have copied this from google...please DON'T mark brainliest)
hope it helps..Just as elastic energy of a rubber band increased when stretched

Answer 2

angular strain is define as the potential energy of a molecule when their bond angles deviate from ideally expected values,

White phosphorus(P4) has a basic tetrahedral unit where four P atoms are arranged in the four corners of a tetrahedron joined together by a total of six single bonds i.e each P atom makes bond with 3 other P atoms to complete its octet leading to reorientation of orbitals thus resulting in a bond angle of 60 deg. Due to a highly strained system, P4 is unstable and very reactive

hope it may help you