Question

Diagram of the adjacent picture frame has outer dimensions $28cm\times 24cm$ and inner dimensions $20cm\times 16cm$. Find the area of the shaded part of a frame, if the width of each section is the same

Answer 1

Given:

outer dimensions $28cm\times 24cm$ and inner dimensions $20cm\times 16cm$

Area of shaded region =$(areaEFJI-areaEFGH)$+ 2 $\times$ area $△AIH$

= $(20\times 20-16\times 20)+2\times \frac{1}{2}\times 4\times 4$

= $(400-320)+16=80+16=96{cm}^2$