# 15.2.1 Trigonometry, PT3 Focus Practice

 
 
15.2.1 Trigonometry, PT3 Focus Practice
 

 
Question 1:
 
Diagram below shows a right-angled triangle ABC.
 

It is given that    $\mathrm{cos}{x}^{o}=\frac{5}{13}$   , calculate the length, in cm, of AB.
 
 

Solution:
     

 
 
 
 
 
Question 2:
 
In the diagram, PQR and QTS are straight lines.

 
 
 
 
 
It is given that $\mathrm{tan}y=\frac{3}{4}$ , calculate the length, in cm, of RS.
 
 

Solution:
     

 
 
 
 
 
Question 3:
 
In the diagram, PQR is a straight line.
 
 
 
 
 
 It is given that   $\mathrm{cos}{x}^{o}=\frac{3}{5}$  , hence sin yo =
 
 
 
 
Solution:
 
 

 
 
 

 
 
 
 
 
Question 4:
 
Diagram below consists of two right-angled triangles.
 

 
 
 
 
Determine the value of cos xo.
 
 

Solution:
     
 

 
 
 
 
 
Question 5:
 
Diagram below consists of two right-angled triangles ABE and DBC.
 
ABC and EBD are straight lines.

 
 
 
It is given that
 
(a)  Find the value of tan xo.
 
(b)   Calculate the length, in cm, of ABC.
 
 

Solution:
 
(a)
 
   
 
 
 
(b)