Answer:
Perpendicular means like making 4 right angles at the intersection, right? So do a light directly upwards through line t from point a. And for 2, do a line from point a to the center of BC, B to the center of AC, and C to the center of AB
Step-by-step explanation:
Answer:
36,000 possible codes.
Step-by-step explanation:
I guess you want the total number of arrangements possible.
The first digit can be any number from 0 to 8. the middle numbers must each be any number from 0 to 9 and the last digit must be 2,4,6 or 8.
So the number of arrangements possible = 9 * 10 * 10 * 10 * 4
= 36,000.
It will take 60 more minutes to complete the entire bookshelf
40%+60%=100% of the bookshelf
20+20+20=60
