Three students attempt to define what it means for AB and CD to be perpendicular. o
D
B
Can you match the teacher's comments to the definitions?
Definition of perpendicular lines
Teacher's comments
Daniela's definition: AB is perpendicular
Please rework your definition to use more precise
to CD is the measure of ZAOC equals
mathematical language.
the measure of LAOD.
Oris definition: AB is perpendicular to
CD i AB and CD intersect perfectly
sideways.
Well done! I hadn't previously considered defining
perpendicular lines in terms of a rigid transformation like
rotation, but by golly it works!
Kaori's definition: AB is perpendicular to
Dit one line can be mapped to the other
by a rotation about point of 90
Well done! Because the measure of ZCOD is 180° (by
the definition of a straight angle), the measures of angles
ZAOC and ZAOD must both be 90.
4 of 7

x=12 units bd= 10 units

step-by-step explanation:

the answer is true.

step-by-step explanation:

a

b

d

step-by-step explanation:

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.