Assertion: triangle's number | /r/HasProperty | 3 × 2 =) 6
Facets:
Source sentences:
text: For example, the third triangular number is (3 × 2 =) 6, the seventh is (7 × 4 =) 28, the 31st is (31 × 16 =) 496, and the 127th is (127 × 64 =) 8128.