the abswer of this question is c
To find his age 4 years ago, you need to subtract 4 from his current age.
His current age is Y, so his age 4 years ago is: y - 4
Answer:

Step-by-step explanation:
22.5 degrees is half of 45 degrees (special angle for which we know exactly the value of all three basic trigonometric functions (sine, cosine, and tangent).
So we start recalling the formula for tangent of a half angle: 
We need just the values of:

and of

to answer the question. Then, we use those values in the original formula for tangent of a half angle:

Answer: 35
Step-by-step explanation:
Angles in a triangle add to 180 degrees, so in triangle ABC,
.
Sp, by the corresponding angles theorem, <u>x=35</u>