How do I do this? I need answers to 2 decimal places, please. Thanks :)

Step-by-step explanation:

perimeter = 30+(2×25)+(½×3.14×30)

= 30+50+47.1

= 127.1 cm

Area = (25×30)+ (½×3.14×15²)

= 750 + 353.25

= 1.103.25 cm²

Explanation:

Divide the figure so we have a semicircle on the left and a rectangle on the right. The rectangle is 30 by 25. The semicircle has diameter 30.

If we consider a full circle of diameter 30, then its circumference is exactly C = pi*d = pi*30 = 30pi centimeters.

But we only have half a circle, so we cut that in half to get 30pi/2 = 15pi. That's the distance around the curved portion of this diagram. The straight line portions are handled as exactly as you expect.

Add up the distances around the outer edges to get:

15pi+25+30+25 = 15pi+80

The exact perimeter, in terms of pi, is 15pi+80 centimeters.

To get an approximation of this, we can use pi = 3.14 to get

15*pi + 80 = 15*3.14+80 = 127.1 cm

To get a better approximation, use more decimal digits in pi. Or you can let your calculator handle the decimal digits of pi (in other words, use the stored version of it).

a) one student is chosen from classroom a, then a student is chosen from classroom b.  

step-by-step explanation:

independent events are ones in which the probability of one event does not affect the probability of the second event.

one student is chosen from classroom a; this does not affect the chances of choosing a student from classroom b.   this makes these independent events.

when one card is chosen from a standard deck and then set aside before a second card is chosen, the probability of the second card being chosen changes.   this makes them dependent events.

when one student is chosen from classroom a and then a second student is chosen from classroom a, the probability of choosing the second student changes.   this makes them dependent events.

when a letter is chosen from the alphabet and then a second letter is chosen, the probability of choosing the second letter changes.   this makes them dependent events.