Explanation:
let the width be x and length be 4x , as it is 4 times more than width
given,
perimeter = 50 cm
we know,
perimeter = 2l + 2b/w
so,
2l + 2b = 50
after inserting the values we got,
→ 2(4x) + 2(x) = 50
→ 8x + 2x = 50
→ 10x = 50
→ x = 50/10 = 5
→ x = 5
therefore, length = 4x = 4×5 = 20 cm
hope this answer helps you dear....take care and may u have a great day ahead!