Triangle a has a height of 2.5 cm and a base of 1.6 cm. the height and base of triangle b are proportional to the height and base of triangle a. which of the following could be the height and base of triangle b? choose 3 answers: a. height: 2.75 base: 1.76b. height: 9.25 base: 9.16c. height: 3.2    base: 5d. height: 1.25 base: 0.8e. height: 2      base: 1.28

A, D, E

Step-by-step explanation:

The ratio height : base is ...

... 2.5 : 1.6

... = 25 : 16

... = 1.5625 : 1

You can eliminate the bogus answers B and C because ...

... B: the numbers are too close together. The larger would need to be near 13 for the smaller one to be 9.

... C: the base is larger than the height, so the ratio is less than 1, not greater than 1.

Comments on other answers

A: the scale factor is 1.1

D. the scale factor is 0.5

E. the scale factor is 0.8

1/4 and 8/3 because:

the reciprocal if 4 is 1/4 because 4 is used as 4/1 and the opposite of that is 1/4. the opposite of 3/8 is 8/3 so that is the answer.

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12