7² + 24² = c²  compare that equation to the Pythagorean theorem:

a²  + b² = c²

So a = 7, b = 24, 

c² = 7² + 24² = 49 + 576 = 625

c = √625 

c = 25

That suggests this right triangle:




Capital letters A.B, and C indicate the three angles, 
Small letters a,b, and c represent the three sides 
opposite the corresponding angles.

The side "a" is the side opposite (across the triangle) from angle "A"
The side "b" is the side opposite (across the triangle) from angle "B"
The side "c" is the side opposite (across the triangle) from angle "C"
The angle "C" is normally chosen as the 90° angle in a right triangle.
The longest side "c", which is opposite the right angle C is called the
"hypotenuse"
The side "a" is the side adjacent (next to) the acute angle B
The side "b" is the side adjacent (next to) the acute angle A

As the other tutor mentioned, you didn't tell which angle to find the
trigonometric ratios of, so I'll do both.  The abbreviations for the
six trig ratios are

sine = sin( )
cosine = cos( )
tangent tan( )
cotangent = cot( )
secant = sec( )
cosecant = csc( )

and you must always put the angle in parentheses to indicate
which angle you are talking about.

If you are talking about acute angle A then

sin(A) =  =  = 
cos(A) =  =  = 
tan(A) =  =  = 
cot(A) =  =  = 
sec(A) =  =  = 
csc(A) =  =  = 

If you are talking about acute angle B then

sin(B) =  =  = 
cos(B) =  =  = 
tan(A) =  =  = 
cot(B) =  =  = 
sec(B) =  =  = 
csc(B) =  =  = 

Notice the Cofunction identities: 

sin(A)=cos(B), cos(A)=sin(B), tan(A)=cot(B), 
cot(A)=tan(B), sec(A)=csc(B), csc(A)=sec(B)

Notice the Reciprocal identities:

, , , , , 

, , , , ,  

Edwin