Question

math question on picture

Answer 1

Answer:

28 cm

Step-by-step explanation:

let the unknown side be x , then

using Pythagoras' identity in the right triangle

x² + 21² = 35²

x² + 441 = 1225 ( subtract 441 from both sides )

x² = 784 ( take square root of both sides )

x = $\sqrt{784}$ = 28

Answer 2

Answer:

the unknown side is 28

Step-by-step explanation:

$a^{2} + b^{2} = c^{2} \\c = 35\\a = 21\\21^{2} + b^{2} = 35^{2}\\441 + b^{2} = 1225\\b^{2} = 1225 - 441\\b^{2} = 784\\b = \sqrt{784} \\b = 28$