Answer:
b = 23.3
Explanation:
First, we need to determine whether this is a right or non-right triangle.
We know that the sum of all the angles in a triangle must add up to 180, so we can add angles A and B and subtract the sum from 180:
![180-(40+88)=180-128=52](https://img.qammunity.org/2023/formulas/mathematics/high-school/symau9e76jqgf1mbqg82cturiz8k7g0dma.png)
The 52 indicates that it is a non-right triangle, so we must rely on either the law of sines or law of cosines to find the measure of b.
Given that we have angle A and its resulting side, a, along with angle B, we can use the law of sines:
![(sin A)/(a)=(sin B)/(b)](https://img.qammunity.org/2023/formulas/mathematics/high-school/alsg6y909evy0117cz5yfmjruj8eg0j1vr.png)
![(sin 40)/(15)=(sin 88)/(b)\\ \\ 15*sin 88=b * sin 40\\\\b=(b*sin 40)/(sin 88)\\ \\b=23.3216=23.3](https://img.qammunity.org/2023/formulas/mathematics/high-school/pggvrfhmtu9n2v7go0dglwp3qp6jsw4ww2.png)