What is the length of the diagonal of a square with side lengths 7 square root of 2 ? round to the nearest tenth if necessary?

There is 2 ways to solve this type of question.

Method 1

Formula

a² + b² = c²


Apply the formula

(7√2)² + (7√2)² = c²
c² = 98 + 98
c² = 196
c = √196
c = 14


Ans: The diagonal length is 14cm 




Method 2

Identify the triangle

This is a special triangle
45° - 45° - 90°


Property of the Angles 

x - x - x√2


Find hypotenuse

Given that the non-hypotenuse is 7√2

Hypotenuse =  (7√2)(√2)
Hypotenuse =  7 x 2
Hypotenuse = = 14cm


Ans: The diagonal length is 14cm