Answer:
The value of b is 12.9 cm
The value of a is 15.3 cm
Explanation:
see the attached figure to better understand the problem
Find the value of b
we know that
in the right triangle ABC
The function sine of angle of 40 degrees is equal to divide the opposite side to the angle of 40 degrees (AC) by the hypotenuse (AB)
so

Solve for AC

substitute the given value


therefore
The value of b is 12.9 cm
Find the value of a
we know that
in the right triangle ABC
The function cosine of angle of 40 degrees is equal to divide the adjacent side to the angle of 40 degrees (BC) by the hypotenuse (AB)
so

Solve for BC

substitute the given value


therefore
The value of a is 15.3 cm