Answer:
![\large\boxed{\large\boxed{8.06units}}](https://img.qammunity.org/2021/formulas/mathematics/middle-school/9e3pbxp14trheehwjsu99ghon954cgf5gw.png)
Step-by-step explanation:
The figure is a right triangle with:
- hypotenuse = segment AC
- vertical leg = 7 units
- horizontal leg = 4 units
Hence, you must use Pythagora's theorem, which is valid for all right triangles:
![hypotenuse^2=(leg_1)^2+(leg_2)^2](https://img.qammunity.org/2021/formulas/mathematics/middle-school/pyo0tz7zda83f6po8l9vuyd8jlts01c6n6.png)
Substituting the data:
![hypotenuse^2=(7unit)^2+(4unit)^2=49unit^2+16unit^2=65unit^2](https://img.qammunity.org/2021/formulas/mathematics/middle-school/8hfd4cmpya8jy5sypcq1y8o9ws7livtluy.png)
Square root both sides:
![hypotenuse=√(65unit^2)=8.06unit](https://img.qammunity.org/2021/formulas/mathematics/middle-school/gdc7w9lmfh30bxovhhj3j6s2uul4vxt7iw.png)