49.9k views
3 votes
Can anyone please tell me what I’m doing wrong. It’s not giving me the full marks.

Can anyone please tell me what I’m doing wrong. It’s not giving me the full marks-example-1
User Miles
by
8.6k points

2 Answers

2 votes

Answer:

116 cm^2 to 3 significant figures.

Explanation:

Your calculations are correct. You just haven't corrected the answer to 3 significant figures.

User Joe Todd
by
8.2k points
6 votes

Answer:

Area shaded part = 116 to three sig digs.

Explanation:

I don't know if your answer is correct or not, but the number of sig digs is not. The way the question has been posed is not to 3 sig digs either.

The answer should be 116 if they want it to three sig digs.

Let's see if the answer is correct

Area of the whole circle.

  • Area of a circle = pi*r^2
  • r = 6.5 cm Note: this is 2 sig digs.
  • pi= 3.14
  • Area = 3.14 * 6.5^2
  • Area = 3.14 * 42.25
  • Area= 132.665

Area of unshaded smaller circle

  • pi = 3.14
  • r = 2.3
  • Area = 3.14 * 2.3^2
  • Area = 3.14 * 5.29
  • Area = 16.61

Area of the shaded part

  • Area of shaded part = area of the whole circle - Area of smaller circle
  • Area of the shaded part = 132.66 - 16.61
  • Area of the shaded part = 116.01
  • To 3 sig digs is 116
User Gandolfa
by
8.9k points