It works because 7 x 9 x 10 is the same thing as 7 x 90, since 9 x 10 is just 90. So basically he is just writing more but the answer will still be the same.
Answer:
49pi m^2
Step-by-step explanation:
Area of circle=pi r^2
D=2r=14
r=7
Area of circle =7^2pi=49pim^2
The answer to the question is 13
Answer:
0.42
Step-by-step explanation:
divide 100÷42 then the answer is 0.42