Answer:
The missing value is 2.9mm and cosine was used
Step-by-step 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,
[tex]cos\ (angle) = \frac{Base}{hypotenuse}\\cos\ 79 = \frac{k}{15}\\k = cos\ 79 * 15\\k = 0.1908*15\\k = 2.862[/tex]
Rounding off to nearest tenth
[tex]k= 2.9mm[/tex]
Hence,
The missing value is 2.9mm and cosine was used
