If asked to multiply 18 by 100 quicky, what is the short cut?

18 x 100 = 1,800

Step-by-step explanation:

You take the 100 and you remove the 2 zeros and put them at the back of 18 to get your answer.

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.