Ans: The first identity states that Sine squared plus cosine squared identical one. The second one states that tangent squared plus one is similar to Secant squared. For the last one, it says that one plus cotangent squared is comparable to cosecant squared.
Formulas are:
({sin ^2} heta + {cos ^2} heta = 1)
({cot ^2} heta + 1 = {{ ext{cosec}}^2} heta )
(1 + { an ^2} heta = {sec ^2} heta )