The perimeter of a rectangle is 36 cm, and the ratio of length to width is 5:4. The area of the rectangle is______ ．

The perimeter of a rectangle is 36 cm, and the ratio of length to width is 5:4. The area of the rectangle is______ ．

5 + 4 = 9 (parts); length: 36 △ 2 × 59, = 18 × 59, = 10 (CM); width: 36 △ 2 × 49, = 18 × 49, = 8 (CM); 10 × 8 = 80 (square cm); answer: the area of this rectangle is 80 square cm. So the answer is: 80 square cm

Area of application problems, speed
It is known that the area of parallelogram ABCD is 160 square centimeters, e and F are the midpoint of AD and DC sides respectively, and the area of shadow part is calculated

If the shadow refers to △ def, then its area is 20
If you can't send pictures, you should use words to describe them clearly

Ask a fourth grade math problem (within one hour)
Simple algorithm calculation
1.4*56.8+4.32*4
Okay, 50 points!

(1+0.4)*56.8+4.32*4
=1*56.8+0.4*56.8+43.2*0.4
=56.8+0.4*(56.8+43.2)
=56.8+0.4*100
=56.8+40
=96.8