### Home > INT3 > Chapter 10 > Lesson 10.3.3 > Problem10-194

10-194.

Use the Pythagorean Identity to determine the $x$coordinate of a point on the unit circle whose $y$‑coordinate is $\frac { 3 } { 7 }$.

At any point on the unit circle, the corresponding right triangle has a hypotenuse of $1$.

If you know the length of the vertical leg and the hypotenuse, how can you solve for the horizontal leg?

For any right triangle, $a^{2} + b^{2} = c^{2}$.