Question

14. Find the area of a triangle two sides of which are 18cm, and 10cm and the perimeter is 42cm.
15. The area of the curved surface of a cylinder is 1000 cm and its diameter is 20cm Find the
Height and Volume of the cylinder​

Answer 1

Step-by-step explanation:

14. Let the third side be x

and 18 + 10 + x = 42cm.

x = 42-(18+10)

x= 14cm

All sides: 18,10,14 (cm)

Using Heron's Formula;

√s(s-a)(s-b)(s-c)

s = semiperimeter = 42 / 2 = 21

$\sqrt{} 21(21 - 18)(21 - 14)(21 - 10) =$

$\sqrt{21 \times 3 \times 7 \ \times 11 = }$

$21 \sqrt{11} \\ \: cm2$

15. Radius: D/2

20/2 = 10cm

CSA of cylinder: 2πrh = 1000cm

2 * 22/7 * 10 * h = 1000 cm

440/7 * h = 1000cm

h = 1000*7/440

h = 175/11 cm

Volume of Cylinder:

πr²h = 22/7 * 10² * 175/11

= 5000 cm³

(After Further Calculation)