Respuesta :

Answer:

QR = 17 cm

Step-by-step explanation:

Δ RST is a 5- 12- 13 triangle with hypotenuse RT = 13 cm , then

TS = 5 cm and PT = 2 × 5 = 10 cm

So PS = 10 + 5 = 15 cm

PS is parallel to the vertical line from vertex Q and intersects the horizontal line projected from SR of length 20 - 12 = 8 cm

Using the right triangle formed calculate QR using Pythagoras' identity

QR² = 15² + 8² = 225 + 64 = 289 ( take square root of both sides )

QR = [tex]\sqrt{289}[/tex] = 17