Use cosine to find the missing value round to 2 decimal places #trigonometry

1. 17.27 cm

2. 19.32 cm

3. 24.07°

4. 36.87°

Step-by-step explanation:

1. Determination of the value of x.

Angle θ = 46°

Adjacent = 12 cm

Hypothenus = x

Using cosine ratio, the value of x can be obtained as follow:

Cos θ = Adjacent /Hypothenus

Cos 46 = 12/x

Cross multiply

x × Cos 46 = 12

Divide both side by Cos 46

x = 12/Cos 46

x = 17.27 cm

2. Determination of the value of x.

Angle θ = 42°

Adjacent = x

Hypothenus = 26 cm

Using cosine ratio, the value of x can be obtained as follow:

Cos θ = Adjacent /Hypothenus

Cos 42 = x/26

Cross multiply

x = 26 × Cos 42

x = 19.32 cm

3. Determination of angle θ

Adjacent = 21 cm

Hypothenus = 23 cm

Angle θ =?

Using cosine ratio, the value of θ can be obtained as follow:

Cos θ = Adjacent /Hypothenus

Cos θ = 21/23

Take the inverse of Cos

θ = Cos¯¹(21/23)

θ = 24.07°

4. Determination of angle θ

Adjacent = 12 cm

Hypothenus = 15cm

Angle θ =?

Using cosine ratio, the value of θ can be obtained as follow:

Cos θ = Adjacent /Hypothenus

Cos θ = 12/15

Take the inverse of Cos

θ = Cos¯¹(12/15)

θ = 36.87°