Answer:
![\huge\boxed{\sf x = 8.2}](https://img.qammunity.org/2023/formulas/mathematics/college/j2238wlfqwlwxan7qhtd7w5m2f6tqusmjn.png)
Explanation:
Since it is a right-angled triangle, we will apply Pythagoras Theorem.
Given are:
Base = 16
Perpendicular = x
Hypotenuse = 18
Pythagoras Theorem:
![\sf (Hypotenuse)^2=(Base)^2+(Perpendicular)^2](https://img.qammunity.org/2023/formulas/mathematics/high-school/brusd1o7qnrlydwzbozdzdk9wv9nvp3aon.png)
(18)² = (16)² + (x)²
324 = 256 + x²
Subtract 256 to both sides
324 - 256 = x²
68 = x²
Take sqrt on both sides
8.2 = x
x = 8.2
![\rule[225]{225}{2}](https://img.qammunity.org/2023/formulas/english/college/eq413d752mwtrwwenrzwldxt4w1olmf1b3.png)