Recall,
Secø = 1/Cosø
Given that
secø= 10/3, it means that
1/Cosø = 10/3
If we reverse both sides of the equation, it means that
Cosø/1 = 3/10
Cosø = 3/10
Recall, Cosø = adjacent side/hypotenuse
Thus,
adjacent side = 3
hypotenuse = 10
We would draw the right angle triangle below
looking at the right angle triangle,
opposite side = x
To find x, we would apply the pythagorean theorem which is expressed as
hypotenuse^2 = opposite side^2 + adjacent side^2
We know that
Sinø = opposite side/hypotenuse
Sinø = 9.54/10
Sinø = 0.954