Answer
$sinA=\frac{BC}{AB}=\frac{20}{29}$
$cosA=\frac{AC}{AB}=\frac{21}{29}$
$tanA=\frac{BC}{AC}=\frac{20}{21}$
Work Step by Step
According to Pythagorean theorem
$(AB)^2=(AC)^2+(BC)^2$
This can be rearranged as:
$(BC)^2=(AB)^2-(AC)^2$
We plug in the known values to obtain:
$(BC)^2=(29)^2-(21)^2=(20)^2$
$\implies BC=20$
Now, we can find the trigonometric functions as
$sinA=\frac{BC}{AB}=\frac{20}{29}$
$cosA=\frac{AC}{AB}=\frac{21}{29}$
$tanA=\frac{BC}{AC}=\frac{20}{21}$
