Trigonometric function

\begin{tikzpicture}[scale=3] \coordinate (A) at (0,0); \coordinate (B) at +(1.5,1); \coordinate (C) at +(1.5,0); \draw (A) -- node[above] {\(h\)} (B) -- node[right] {\(o\)} (C) -- node[below] {\(a\)} (A) ; \pic[draw, <->, angle radius=1cm, "$\theta$"] {angle = C--A--B }; \pic[draw, angle radius=0.3cm] {right angle = B--C--A }; \end{tikzpicture} ParseError: No such environment: tikzpicture at position 7: \begin{̲t̲i̲k̲z̲p̲i̲c̲t̲u̲r̲e̲}̲[scale=3] \coor…sin⁡θ=ohcos⁡θ=ahtan⁡θ=oacsc⁡θ=hosec⁡θ=hacot⁡θ=ao