As character names:

U+22BF RIGHT TRIANGLE character (⊿)

As raw characters:

⊿

As a string of HTML entities:

⊿

Decoder output:

Byte number 1 is decimal 226, hex 0xE2, octal \342, binary 11100010
This is the first byte of a 3 byte sequence.

Byte number 2 is decimal 138, hex 0x8A, octal \212, binary 10001010
This is continuation byte 1, expecting 1 more.

Byte number 3 is decimal 191, hex 0xBF, octal \277, binary 10111111
This is continuation byte 2, expecting 0 more.

U+22BF	RIGHT TRIANGLE