Lesson Example Discussion Quiz: Class Homework |
Step-3 |
Title: Area of a circle |
Grade: 8-a Lesson: S4-L4 |
Explanation: Let us verify the answer here with the steps. |
Description:
| Step | Type | Explanation | Answer |
|---|---|---|---|
1 |
Problem |
The circumference of a circular disc is 62.8 cm. Find its area.(Use π = 3.14) |
|
2 |
Hint |
Formula used |
\$"circumference" = 2\pi r\$ \$"Radius(r)" = "circumference" / (2\pi)\$ |
3 |
Step |
Given that, Circumference of a circular disc = |
62.8 cm |
4 |
Step |
Radius of circular disc |
\$"Radius(r)" = "circumference" / (2\pi)\$ |
5 |
Step |
Substitute the given value of circumference and the value of \$\pi\$ |
\$r = (62.8 cm) / (2 \times 3.14)\$ \$r = (62.8 cm) / (6.28)\$ r = 10 cm |
6 |
Step |
\$"Area" = \pi r^2\$ Substitute the value of pi and the calculated value of |
\$Area (A)= 3.14 \times 10^2 \$ ⇒ \$Area (A)= 3.14 \times 100 \$ ⇒ \$A = 314 cm^2\$ |
7 |
Step |
Therefore, the area of a circular disc is |
\$314 cm^2\$ |
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