Question

How do you find this ?

Answer 1

Option D : 22°

Explanation:

The relationship between angle C and the two legs of the right triangle ie AB and BC is

`\tan C = (AB)/(BC)\\\\\text{We have AB = 2, AC = 5}\\\\\rightarrow \tan C = \frac[2}{5}= 0.4\\\\m\angle C = \tan^(-1)(0.4) = 21.8^\circ`

Rounded to the nearest degree this would be 22°

Option D

Answer 2

D

Explanation:

using either the sine or cosine or tangent ratios in the right triangle , that is

sin C =
`(opposite)/(hypotenuse)` =
`(AB)/(AC)` =
`(2)/(√(29) )` , then

∠ C =
`sin^(-1)` (
`(2)/(√(29) )` ) ≈ 22° ( to the nearest degree )

or

cos C =
`(adjacent)/(hypotenuse)` =
`(BC)/(AC)` =
`(5)/(√(29) )` , then

∠ C =
`cos^(-1)` (
`(5)/(√(29) )` ) ≈ 22° ( to the nearest degree )

or

tan C =
`(opposite)/(adjacent)` =
`(AB)/(BC)` =
`(2)/(5)` , then

∠ C =
`tan^(-1)` (
`(2)/(5)` ) ≈ 22° ( to the nearest degree )