 What is the angle at which she is leaning? The first step is to draw a diagram, labelling the two known sides with their values, and their names, based on where the angle is:  Now decide which trig function you can write, using these named sides.  Next, fill in the values of the sides, and work out the decimal.  Since your calculator has the values for each trig function stored in its memory for every angle, it will tell you which angle has a TAN of 2.8 
So Robin must be leaning at an angle of 70 degrees. Notice that we solved this using a 70 degree right triangle drawn small on the screen. We could have used a large triangle drawn on paper, or any other size triangle ... for any particular right triangle (in this case, with a 70 degree corner angle), the fractions you can make from the sides are always the same, because all the triangles you can draw, regardless of their size, are 'similar'. That's why your calculator can keep them stored ... for a 70 degree angle in a right triangle of any size, the opposite side divided by the adjacent side is always 2.8 |