Answer:
10) - 45 degrees
12) 0 degrees
Explanation:
10)
Find the x and y components that define the vector that joins C with D:
x-component: -4 - (-8) = - 4 + 8 = 4
y-component: 4 - 8 = -4
use the tangent function to find the angle
:
![tan(\theta)=(y-comp)/(x-comp)=(-4)/(4) = -1\\\theta = -45^o](https://img.qammunity.org/2021/formulas/mathematics/college/48foaz89m0c8v68duabk59hgvlvblbb9ja.png)
12)
Find the x and y components that define the vector that joins A with B:
x-component: 7 - 4 = 3
y-component: - 1 - (-1) = -1 + 1 = 0
use the tangent function to find the angle
:
![tan(\theta)=(y-comp)/(x-comp)=(0)/(3) = 0\\\theta = 0^o](https://img.qammunity.org/2021/formulas/mathematics/college/2h7p2y757nbju9lm191hu1p2qmbocote1b.png)