CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
Question

A piece of cheese needs to be covered in a paper of area 120 sq cm as shown in the below figure. Find the possible height of the triangular face of the pyramid.


A
5 cm
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
3 cm
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
7 cm
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
6 cm
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 7 cm
It is given that, total surface area of the square pyramid = 120 sq cm

This pyramid contains one square base and 4 triangular faces.


Base area = side × side

Side of the square = 6 cm

Base area = 6 × 6 = 36 sq cm


Total surface area = Base area + 4 × area of one triangular face

Area of triangular face = 12× base × height

Base of the triangle = 6 cm

Let, the height of the triangle = h

Total surface area = Base area + 4 × area of one triangular face

120 = 36 + 4 × 12× 6 × h

120 - 36 = 12h

84 = 12h

h = 8412

= 7 cm

Hence, the possible height of the pyramid = 7 cm

flag
Suggest Corrections
thumbs-up
0
BNAT
mid-banner-image