P = (L + W) × 2

P = (5 + 20) × 2

P = (25) × 2

P = 50

Answer: 50

LET :

• 20 be the width
• ( 20 × 2 + 5 ) or 45 be the length

FORMULA:

• p = 2 ( w = 1 )

Solution

• p = 2 (w +1)
• p = 2 (20+45)
• p = 2 (65)
• p = 130

Conclusion:

• the perimeter of the rectangle is 130 cm

Answer:

• 130 cm