Question

The cross section of a piece of metal 2 m in length is shown. Calculate the area of cross section.

Answer 1

Divide the figure into 1 rectangle and 1 triangle.
Dimensions of the rectangle:
length = 8cm
breadth = 6cm
Area of rectangle
= length x breadth
= 8 x 6
= 48cm²      ...(1)
Dimensions of the triangle:
base
= 12 - 6
= 6cm
height
= 8 - 5
= 3cm
Area of a triangle

= `(1)/(2) xx "b" xx "h"`

= `(1)/(2) xx 6 xx 3`
= 9cm²     ...(2)
Area of the cross section
= 48 + 9
= 57cm²
∴ Area of the cross section is 57cm².