Checking and securing understanding of cosine problems

12 questions

1. Two shapes are similar if the only difference between them is their ___. Their side lengths are in the same proportions.
2. Triangle ABC and triangle DEF are similar. What is the length of side x?
3. Triangle ABC and triangle DEF are similar. What is the length of side x?
4. The two triangles are similar. What is the size of the angle marked x?
5. What is the approximate value of \cos(60^\circ)?
6. What is the approximate value of \cos(30^\circ)?
7. Work out the length of x, given that these two triangles are similar.
8. Work out the length of x, given that these two triangles are similar.
9. For a right-angled triangle, the cosine ratio is \cos(\theta)=\frac{\text{adj}}{\text{hyp}}, where \theta is the angle in degrees. Which of these are equivalent forms?
10. Which of the following equations are correct when finding the angle n^\circ in the equation: \cos(n^\circ)=0.57?
11. Which of these is correct for this triangle?
12. Calculate the length of x to 2 decimal places.

License: OGL