# What is the Cartesian form of (81,(3pi)/8)?

Jul 2, 2017

$\left(31.0 , 74.8\right)$

#### Explanation:

We're asked to find the Cartesian (rectangular) form of a polar coordinate.

This is done by

$x = r \cos \theta$

$y = r \sin \theta$

Therefore,

$x = 81 \cos \left(\frac{3 \pi}{8}\right) \approx 31.0$

$y = 81 \sin \left(\frac{3 \pi}{8}\right) \approx 74.8$

The rectangular form is thus

$\left(31.0 , 74.8\right)$