Exercise 11.4

On a square cardboard sheet of area \[784\] \[c{{m}^{2}}\], four congruent circular plates of maximum size are placed such that each circular plate touches the other two plates and each side of the square sheet is tangent to two circular plates. Find the area of the square sheet not covered by the circular plates.

Given Area of the square = \[784\] \[c{{m}^{2}}\] Hence Side of the square = \[\sqrt{Area}\] = \[\sqrt{784}\] = \[28\] cm Given that the four circular plates are congruent, Therefore diameter of...

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In Fig. 11.17, ABCD is a trapezium with AB || DC, AB = \[18\] cm, DC = \[32\] cm and distance between AB and DC = \[14\] cm. If arcs of equal radii \[7\] cm with centres A, B, C and D have been drawn, then find the area of the shaded region of the figure.

Solution Given AB = \[18\] cm, DC = \[32\] cm Given, Distance between AB and DC = Height = \[14\] cm We know that  Area of the trapezium = (\[1/2\]) × (Sum of parallel sides) × Height =...

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Sides of a triangular field are \[15\] m, \[16\] m and \[17\] m. With the three corners of the field a cow, a buffalo and a horse are tied separately with ropes of length \[7\] m each to graze in the field. Find the area of the field which cannot be grazed by the three animals.

Solution From the given question, We got Sides of the triangle are \[15\] m, \[16\] m and \[17\] m. Then, perimeter of the triangle = \[(15+16+17)\] m = \[48\]m Therefore, Semi-perimeter of the...

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