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Question
A design is made up of four congruent right triangles as shown in the given figure. Find the area of the shaded portion.
Solution
Area of one right angled triangle = `1/2 BA xx BG = 1/2 xx 10 × 30` = 150 cm2
So, area of 4 right angled triangles = 4 × 150 = 600 cm2 ......[∵ All the right-angled triangles are congruent]
∵ Area of square = (Side)2 .......[GC = 10 cm, because all the triangles are congruent]
Area of portion ABCD = (30 + 10)2 = 402 = 1600 cm2
∴ Area of shaded portion = 1600 – 600 = 1000 cm2
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