# Math

posted by on .

A photo width of 8cm, length of 14cm .if the perameter of photo is increased by 5o % , which dimension is for new perimeter.
options are:
16cm by 28cm
12cm by 21cm
4cm by7cm
8cm by28 cm
i chose the first option cuz it increased 50.but i ma not sure if i am right.

• Math - ,

Present perimeter: 16 + 28 = 44

44 * 1.5 = 66 = new perimeter

The perimeter you chose is 32 + 56 = 88

Check out the other options. Which produces a perimeter of 66 cm?

• Math - ,

8cm by 28 cm ?
I am confused . Geometery is not my thing .

• Math - ,

P = 2L + 2W

Present perimeter:

P = 2(8) + 2(14)

P = 16 + 28

P = 44

• Math - ,

it make sense so , just apply the Perameter formula and put the valuse so answers is 44 then 44*1.5 = 66.

But How i have deal with increased 50% deminsion thing .
please can you simplfy this .

• Math - ,

Use trial and error.

Using your choices, figure out the perimeter for each set of dimensions.

P = 2L + 2W

Which produces a perimeter of 66?

• Math - ,

12cm by 21cm = 2*33= 66
??

• Math - ,

Let's check it out.

P = 2(21) + 2 (12)
P = 42 + 24
P = 66

Right!

• Math - ,

Thanks.

• Math - ,

You're welcome.

• Math - ,

there is options like 4cm by 7cm,8cm by 28cm 12cm by21cm16cm by28cm.how do I go to this options from 66.