The area of a square garden is 200 m². how long is the diagonal?

Area of a square: side²

200=side²

side=√200=14.14

Pythagoras therorem:

hypotenuse²=leg₁² + leg₂²

In this case:

hypotenuse=diagonal

leg₁=leg₂=side

Therefore:

hypotenuse² = (14,14 m) ² + (14,14 m) ²

hypotenuse²=200 m²+200 m²

hypotenuse²=400 m²

hypotenuse=√ (400 m²) = 20 m

The diagonal would be 20 m.