Answer:
AD = 3
Step-by-step explanation:
Pythagoras theorem formula: a² + b² = c² (c being the hypotenuse, the longest side of the triangle).
Using this formula, you can easily say that c²-b²=a². c=5, b=4, making the equation 5² - 4² = a ².
Expanding the formula, you'll get 25 - 16 = a².
25 - 16 = 9.
This means that 9 = a².
To find a, you need to root 9. Using a calculator, you'll know that this number is 3, meaning that AD = 3.
