Please helpp
What is the area of the purple region?
What is the area of the green region?

what do we need to know:

the radius of the semi circles;

the area of:

  purple region = area of a circle = pi * r^2;

  green region = base * height;

what we know:

the base, 28m;

what the sum of the two diameters is, 28;

the length of a single diameter, 14;

what we can assume:

the two semi-circles are equal, as otherwise i cannot see a way to answer this;

the radius of the two semi-circles, 7m as the two diameters = 28, & d/2 = r

what does that mean:

the height is 17m

green region area = 476 m^2

purple region area is = 153.96 m^2

go hook jvc hgv cj xk jvc 6756

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.