Answer:
The answer to your question is: a = 3.5 units
Step-by-step explanation:
Right triangle
to find a we need to use the trigonometric function cosine
cosine Ф = opposite leg / hypothenemus
Clear opposite leg from the equation
opposite leg = hypothenemus x cosine Ф
a = opposite leg = 5 x cosine 45
a = 5 x 0.70
a = 3.5 units
