Respuesta :

Answer

x = 18 cm

Step-by-step explanation:

Here, we want to calculate the value of x

let half of x = b

so b is the base of each right-triangle

As we can see, the triangle is isosceles

we can calculate the length of the base of one of the smaller right angled triangle and multiply by 2 to get the full x length

According to Pythagoras’ , the square of the hypotenuse equals the sum of the squares of the two other sides

15^2 = 12^2 + b^2

225 = 144 + b^2

b^2 = 225-144

b^2 = 81

b = √81

b = 9

but x = 2b

x = 2(9)

x = 18 cm