How many chinese girls can i fit in a 50cm by 50cm by 60cm box?

The lines shown below are parallel. if the green line has a slope of -1, what is the slope of the red line?

One integer is 8 times another. if the product is 72, then find the integers

1. 2. ∠b and ∠y are right angles. 3.? 4.? which two statements are missing in steps 3 and 4? ∠x ≅ ∠c △abc ~ △zyx by the sas similarity theorem. ∠b ≅ ∠y △abc ~ △zyx by the sas similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem.