Question

Two pillars of height 8 ft each with four faces of the gate of a stadium have one-one pyramid of height 4 ft each having same base on their tops. The base of each pillar is 6 ft × 6 ft. If the pillars with pyramid are painted at rate of Rs 89 per sq.ft , what will be the total cost? [ Please include figure too]

Help!! ~Thanks in advance! :)​

Answer 1

☆Answer :

Total cost painted = 44,856

Answer in the picture.

Answer 2

• ₹ 44856

Explanation:

There are 2 pillars, two right prisms of dimensions 6x6x8 ft, two right pyramids of dimensions 6x6x4 ft on top of prisms.

There will be 4 faces of each painted.

Area of each prism face:

• 6*8 = 48 ft²

Total area of prism faces:

• 8*48 = 384 ft²

Slant height of pyramid faces:

• s = √h²+(a/2)², where h- height of pyramid, a - side of base
• s = √4²+(6/2)²= √16+9 = √25 = 5 ft

Area of each face of pyramid:

• A = (1/2)*6*5 = 15 ft²

Total area of pyramid faces:

• 8*15 = 120 ft²

Total area to be painted:

• 384 + 120 = 504 ft²

Cost of paint:

• 504*89 = 44856