Answer:
Her cousin used Yard to measure the wall.
Explanation:
Firdaus measured the length of the wall and got 9 feet.
Her cousin measured the same distance and said that it was 3.
To find the answer, we have to use division.
Let "x" the divisor which divide 9 and gives the answer 3.
9 ÷ x = 3
3x = 9
To find x (divisor) we need to divide both sides by 3, we get
3x ÷ 3 = 9 ÷ 3
x = 3
So 1 unit cousin's measure = 3 feet Firdaus measure
We know that 1 yard = 3 feet.
Therefore, her cousin used Yard measure to measure the wall.