# How do you calculate #cos^-1 (2.3/5.4)#?

##### 1 Answer

Jun 4, 2016

64.8°

#### Explanation:

The question is asking " What angle in a right-angled triangle has the ratio of the adjacent side to the hypotenuse as

First find the ratio in decimal form by dividing.

This is the value of the Cos of our known angle. To find the angle you either need to use a calculator or a table.

Do the calculation on a calculator, then press 2nd function/shift and Cos.

Some calculators need the = sign pressed, others will give tha answer immediately.

You can also key it in as:

shift cos (2.3÷5.4) =