Page 41 - RME-Based Bilingual E-Module

LEARNING ACTIVITIES 2

Activities 2.5 Examples

Let’s Learn!

Problem of Cone Surface Area
Aisyah will make a cone-shaped birthday hat from paperboard coated
with gold paper with 35 cm of height and 24 cm of diameter. Calculate

the minimum area of gold paper required by Aisyah!

Solution:

Known : d = 24 cm  r = ½ d = ½ x 24 = 12 cm
Height = h = 35 cm
Asked : Minimum Area of Gold Paper = Side Area of Cone

2
2
Answer : s = h + r = 35 + 12 = 1225 + 144 = 1369
2
2
2
s = 1369 = 37 cm
Side Area of Cone =  r s
= 3,14 x 12 x 37
= 1394,16 cm
2
So, minimum area of gold paper required by Aisyah is 396

2
cm .

Problem of Cone Volume
An ice cream cone with 18 cm of height and 8 cm of diameter. Count the

volume of ice cream!

Solution:
Known : d = 8 cm  r = ½ d = ½ x 8 = 4 cm

h = 18 cm
Asked : Volume of Ice Cream
2
Answer : Volume of cone = 1/3  r h
= 1/3 x 3,14 x 4 x 4 x 18
= 301,44 cm
3
3
So, volume of ice cream is 301,44 cm .

RME-BASED BILINGUAL E-MODULE— 14