Question

A rectangular image of length 5 cm and width 7 cm is magnified in a studio. On magnification, 1 cm of the image represents 15cm. Find the perimeter of the rectangle in the magnified image.

Answers:
360 cm
180 cm
440 cm
84 cm

Answer 1

238 cm

Explanation:

so we have a scale factor of 17: 1

originally we had the dimensions: 3cm by 4m

now we have 3*17 by 4*17 = 51 cm by 68 cm

Perimeter = 2*51 + 2*68 = 238 cm

Answer 2

360 cm

Explanation:

The height of the magnified image is the product of the height of the original image and the scale factor.

h=15(7) cm.

Simplify.

h=105 cm.

The width of the magnified image is the product of the width of the original image and the scale factor.

w=15(5) cm.

Simplify.

w=75 cm.

So, the perimeter is

P=2(75)+2(105) cm.

Simplify.

P=360 cm.

Therefore, the perimeter of the painting is 360 cm.