To find the percentage difference between two numbers, we first need to find the absolute difference between them. In this case, the absolute difference between 177 and 87 is 90 (177 - 87 = 90).

Next, we need to find the average of the two numbers. The average of 177 and 87 is (177 + 87) / 2 = 132.

Now, we can calculate the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 177 and 87 is (90 / 132) x 100 = 68.18%.

Therefore, the percentage difference between 177 and 87 is 68.18%. This means that the two numbers are quite different from each other, with a difference of almost 70% of their average value.