Question

Chose the missing side length and the trigonometric ratio you would use to calculate.

Answer 1

The missing value is 2.9mm and cosine was used

Explanation:

Given triangle is a right-angled triangle we can use trigonometric ratios to calculate the missing length.

In the given triangle,

Base = k

Hypotenuse = 15mm

Angle = 79

We will use trigonometric ratio which includes base and hypotenuse.

Using cosine,

`cos\ (angle) = (Base)/(hypotenuse)\\cos\ 79 = (k)/(15)\\k = cos\ 79 * 15\\k = 0.1908*15\\k = 2.862`

Rounding off to nearest tenth

`k= 2.9mm`

Hence,

The missing value is 2.9mm and cosine was used