Question

A metal shop is cutting a rectangular piece of sheet metal with a width of 60 inches and a length of 144 inches. The shaded parts of the diagram represent two rectangular sections, A and B, that will be cut and removed.

Part A :What are the dimensions of section B?​
Part B:What will be the area, in square inches, of the piece of sheet metal after both sections are cut and removed?
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Answer 1

Dimensions of section B = 36 inches, 48 inches

Area of the piece of sheet metal after both sections are cut and removed = 6336 square inches

Explanation:

Given: Width and length of a rectangular piece of sheet metal are 60 inches and 44 inches.

To find: dimensions of section B, the area of the piece of sheet metal after both sections are cut and removed

Solution:

Length of rectangle B = TR = SR - ST = PQ - ST (As SR = PQ being opposite sides of rectangle)

Length of rectangle B = PQ - ST = 60 - 24 = 36 inches

Breadth of rectangle B = UR = QR - QV - VT - TU

Here, QR = PS = 144 inches (opposite sides of rectangle PQRS are equal )

QV = 36 inches

VT = WX = 24 inches ( opposite sides of rectangle WVTX are equal)

TU = 36 inches

So,

Breadth of rectangle B = 144 - 36 - 24 - 36 = 48 inches

Area of rectangle B = length × breadth = 36 × 48 = 1728 square inches

Area of rectangle WVTX = length × breadth = 24 × 24 = 576 square inches

Area of rectangle PQRS = PQ × PS = 60 × 144 = 8640 square inches

Area of the piece of sheet metal after both sections are cut and removed =8640 - ( 1728 + 576 ) = 8640 - 2304 = 6336 square inches