Question

Oblicz Pola trapezów:

1) a- 2⅓ cm
b- 1 ½ cm
h- ⅚ cm

2) a- 1½ dm
b- 2,4 dm
h- 1⅕ dm

3) a- ¼ m
b- 0,5 m

h- ⅕ m

4) a- 16000 km
b- 200 km
h- 200000000 km

Answer 1

zad. 1

                   P= ½( a+b) h

                   P= ½·(2⅓ cm+1½ cm)·⅚  cm

                   P=½·(7/3+ 3/2) 5/6

                   P=½ (14/6+9/6)·5/6

                   P=½ ·23/6 cm ·5/6 cm

                   P=23/12·5/6

                   P= 115/74

                   P= 1 41/74 cm²

                   

 

zad.2        P=½(1½dm+2,4 dm)·1⅕ dm

                P=½(1,5+2,4)·1,2

                p=½·3,9·1,2

                p=0,5·3,9·1,2

                p= 2,34 dm²

 

zad.3     P=½(¼m+0,5 m)·⅕m

             P=0,5(0,25 +0,5)·0,20

             P=0,5·0,75·0,20

             P=0,075 m²

 

zad.4   P=½(16000 km+200 km)·2⁸ km

           P=0,5· 16200 km·2·10⁸km

           P=8100 km·2·10⁸km

           P= 81·10² km·2·10⁸ km

           P=162·10¹⁰ km²