Answer for 7 and 8 and explanation if possible

7. To find the area of a triangle you use base x height /2.  so the base is 10 and the height is 25 so you do 10 x 25 first which is 250 then divide by 2 which gives you 125 so the area of each pennant is 125 cm^2 ( the ^2 means squared)

8. To find the area of a square you do length x Width. Since for a square all sides are the same the length AND the width are both 450cm. Now you just do 450 x 450 which gives you 202,500 cm^2. BUT it asks for an answer written in SQUARE METRES so you have to change 450cm to metres making it 4.5 metres x 4.5 metres = 20.25  SO THE REAL ANSWER IS 20.25 M^2

Hope this helps you out!

#7 The area is 250 squared centimeters 
          Why: The formula 2(1/2B * h)
                    This formula when the numbers are plugged in you take half of the                     base and multiply it by the height and multiply that answer by 2 to                       get your answer.

#8 The area is 2025 squared meters 
       Why: because to find the area of a rectangular prism you use the formula length * width and since it is a square those numbers are the same so in this situation it would 450 * 450  and then take that total and convert the centimeters to meters.