This is the 1393rd most frequent Arabic word.
بمقدار
"بمقدار" means "by an amount" or "to the extent of."
In this case, 'بمقدار' functions to illustrate the decrease 'by an amount of' regarding speed measurement.
انخفضت السرعة بمقدار عشرين كيلومترًا في الساعة.
The speed decreased by 20 kilometers per hour.
This sentence illustrates 'بمقدار' being used to indicate the magnitude of change in the length, as 'by an amount of' five centimeters.
تغير الطول بمقدار خمسة سنتيمترات.
The length changed by 5 centimeters.
Here, 'بمقدار' denotes 'by an amount of', showing a specific quantitative increase in percentage.