ICSE-VIII-Mathematics
17: Special Types of Quadrilaterals Class 8 Maths
- #4In square PQRS : (i) if PQ = 3x - 7 and QR = x + 3 ; find PS (ii) if PR = 5x and QR = 9x - 8. Find QS (i) if PQ = 3x - 7 and QR = x + 3 ; find PS (ii) if PR = 5x and QR = 9x - 8. Find QSAns : (i) sides of square are equal.
PQ = QR
⇒ 3x - 7 = x + 3
⇒ 3x - x = 3 + 7
⇒ 2x = 10
⇒ x = 5
PS = PQ = 3x - 7 = 3×5 - 7 =8 (ii) PR = 5x and QS = 9x - 8
As diagonals of square are equal.
PR = QS
5x = 9x - 8
⇒ 5x - 9x = -8
⇒ -4x = -8
⇒ x = 2
QS = 9x - 8 = 9 ×2 - 8 = 10 (i) sides of square are equal.
PQ = QR
⇒ 3x - 7 = x + 3
⇒ 3x - x = 3 + 7
⇒ 2x = 10
⇒ x = 5
PS = PQ = 3x - 7 = 3×5 - 7 =8 (ii) PR = 5x and QS = 9x - 8
As diagonals of square are equal.
PR = QS
5x = 9x - 8
⇒ 5x - 9x = -8
⇒ -4x = -8
⇒ x = 2
QS = 9x - 8 = 9 ×2 - 8 = 10
- #4-iif PQ = 3x - 7 and QR = x + 3 ; find PSAns : sides of square are equal.
PQ = QR
⇒ 3x - 7 = x + 3
⇒ 3x - x = 3 + 7
⇒ 2x = 10
⇒ x = 5
PS = PQ = 3x - 7 = 3×5 - 7 =8
- #4-iiif PR = 5x and QR = 9x - 8. Find QSAns : PR = 5x and QS = 9x - 8
As diagonals of square are equal.
PR = QS
5x = 9x - 8
⇒ 5x - 9x = -8
⇒ -4x = -8
⇒ x = 2
QS = 9x - 8 = 9 ×2 - 8 = 10