Soviet education printing plate sixth grade first volume mathematics ppt
The radius of a circle is equal to 10? 2=5 The area of a semicircle is equal to the square of 5 times 3. 14? 2=39.25 The triangle area is equal to 10 times 5? 2=25。 A small shadow equals 39.25-25? 2=7. 125。 That is, all shadows are equal to 7. 125 times 3.