Q7 of 99 Page 267

If the length of hypotenuse of an isosceles right-angled triangle is 12√2 cm. Let us write by calculating the area of this triangle.

Given, length of hypotenuse of an isosceles triangle = 12√ 2 cm


Let the equal sides of the isosceles right-angled triangle be x cm


But according to the Pythagoras theorem


⇒ x2 +x2 = (12√ 2)2


⇒ 2x2 = 144 × 2


⇒ x = √ 144


⇒ x = 12 cm


Area of isosceles right-angled triangle


= where x is the equal side of isosceles triangle


Area =


=


=72 cm2


More from this chapter

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5

If length of base of any isosceles triangles is 12 cm and length of each equal side is 10 cm. Let us write by calculating the area of that isosceles triangle.

 6

Perimeter of any isosceles triangle is 544 cm. and length of each equal side is of length of base. Let us write by calculating the area of this triangle.

8

Pritha drew a parallelogram of which length of two diagonals are 6 cm and 8 cm and each angle between two diagonals is 90°. Let us write the length of sides of parallelogram and what type of parallelogram it is.

 9

The ratio of the length of sides of a triangular park of our village is 2:3:4; perimeter of park is 216 meter.

(i) Let us write by calculating the area of the park.


(ii) Let us write by calculating how long is to be walked from opposite vertex of longest side to that side straightly.