Solve the following sub question :
in the adjoining figure, seg `PS bat side QR. If PQ = a, PR = b QS = c and Rs = d` then complete the following activity to prove that (a + b) (a - b) = (c + d) (c - d)
Proof : In `Delta PSQ angle PSQ = 90 ^(@)`
`square^(2) = PS^(2) + square^(2)`
` PS^(2) = square^(2) - square^(2)`
In `Delta PSR, angle PSR = 90^(@)`
`square^(2) = PS^(2) + square^(2)`
`PS^(2) = square^(2) - square^(2) = square^(2) - square^(2)`
`a^(2) - c^(2) = b^(2) - d^(2)`
`a^(2) - b^(2) = C^(2) - d^(2)`
`square xx square = square xx square`