Find 70% of the area of a rectangle with sides 12cm and 50cm

First, let’s find the area of the rectangle – it is equal to the product of its two sides of different sizes:

S = 12 * 50 = 600 cm2.

The resulting area is 100%. Since you need to find 70%, you can make a proportion by designating the required area for X:

X / 70 = 600/100;

X = 600 * 70/100 = 420 cm2.

It could have been easier to act. 70% of the area corresponds to 0.7 of this area, then:

X = 0.7 * 600 = 420 cm2.