द डायमीटर ऑफ द बेस्ट एरिया ऑफ ए राइट सर्कुलर कोन इज 21 मीटर एंड 14 मीटर लेटेस्ट कैलकुलेट द टीचर टू कलर द सरफेस एट द रेट ऑफ 1.5 स्क्वायर मीटर
Answers
Step-by-step explanation:
577 cm².
Step-by-step explanation:
In this question we have to calculate the curved surface area which is represented by the formula
S = πrl
which is different from total surface area of the cone represented by the formula :
Total surface area = πr²+πrl
The diameter of the base of right circular cone = 21 cm
Height of the cone = 14 cm
First we calculate the slant height of the cone by the formula :
l=\sqrt{r^{2}+h^{2}}l=
r
2
+h
2
l = slant height
r = radius = \frac{1}{2}\times 21
2
1
×21 = 10.5 cm
and h = height = 14 cm
=\sqrt{(10.5)^{2}+(14)^{2}}=
(10.5)
2
+(14)
2
=\sqrt{(110.25)+(196)}=
(110.25)+(196)
= \sqrt{306.25}
306.25
l = 17.5 cm
Curved surface area = πrl
\frac{22}{7}\times 10.5\times 17.5
7
22
×10.5×17.5
= 3.14 × 10.5 × 17.5
= 576.975 ≈ 577 cm²
Curved surface area is 577 cm².