Dusan

a) Dusan breaks two same windows, which have a triangular shape with a length of 0.8 m and a corresponding height of 9.5 dm. Find how much dm² of glass he needs to buy for the glazing of these windows.

b) Since the money to fix Dusan has not been, it must go to the paint job advertising posters in the shape of a parallelogram. Its length is 4.9 m, and its corresponding height is 3.5 meters. How many kg of color need to purchase when 1 kg is sufficient for painting the surface of 4 m ²?

c) When Dusan completes painting will return home. He wants to relax in your room. How many m² has his room where the floor is made from 600 parquet tiles? The parquet floor in the room is shaped rhomboid with a side 2.5 dm long and an appropriate height of 0.8 dm.

Correct answer:

a =  76 dm²
b =  5 kg
c =  12 m²

Step-by-step explanation:

$$\begin{gathered} x=0.8\text{m}\to \text{dm}=0.8\cdot 10\text{dm}=8\text{dm} \\ y=9.5\text{dm} \\ a=2\cdot \frac{x\cdot y}{2}=2\cdot \frac{8\cdot 9.5}{2}=76{\text{dm}}^2 \end{gathered}$$

$b=\lceil 4.9\cdot 3.5/4\rceil =5\text{kg}$

$$\begin{gathered} n=600 \\ {x}_1=2.5\text{dm}\to \text{m}=2.5:10\text{m}=0.25\text{m} \\ {y}_1=0.8\text{dm}\to \text{m}=0.8:10\text{m}=0.08\text{m} \\ c=n\cdot x_1\cdot y_1=600\cdot 0.25\cdot 0.08=12{\text{m}}^2 \end{gathered}$$

Try another example