Respuesta :
Answer:
sine A = four-fifths
Step-by-step explanation:
You have a rectangle triangle ABC with hypotenuse AB 35, side CB 28 and side CA 21. The angle C is 90°.
In order to calculate sin A, you take into account that:
[tex]sinA=\frac{opposite\ side\ to\ A}{hypotenuse}[/tex]
The opposite side to angle A is side CB = 28
Hypotenuse = 35
You replace the numeric values of the hypotenuse and side BC in the formula for sinA:
[tex]sinA=\frac{28}{35}[/tex]
In order to simply the fraction, you divide both numerator and denominator by 7:
[tex]sinA=\frac{28/7}{35/7}=\frac{4}{5}[/tex]
hence, the answer is
sine A = four-fifths