Math, asked by shiv5585, 3 months ago

The perimeter of a rectangle whose one side measures 12 cm and diagonal is 20 cm is -
1 point
64 cm
44 cm
56 cm
52 cm
for class 7

Answers

Answered by PIYANSUPAUL
2

i) Length = 24.5 m

Breadth = 18 m

∴ Area of the rectangle = Length × Breadth

= 24.5 m × 18 m

= 441 m2

(ii) Length = 12.5 m

Breadth = 8 dm = (8 × 10) = 80 cm = 0.8 m [since 1 dm = 10 cm and 1 m = 100 cm]

∴ Area of the rectangle = Length × Breadth

= 12.5 m × 0.8 m

= 10 m2

Answered by raheepradeep6306
7

Answer:

The diagonal of a rectangle divides the rectangle into two right angled triangles.

diagonal ( which is the hypotenuse of the two triangles formed ) = 20 cm

side ( which is one the legs of the two triangles formed ) = 12 cm

Using Pythagoras Theorem:

h² = l² + b²

20² = 12² + b²

b² = h² - l²

b² = 20² - 12²

b² = 400 - 144

b² = 256

b = √256

b = 16 cm

Therefore, the length of the second side of the rectangle ( which is the base of the two triangles formed ) is 16 cm

Perimeter of a rectangle = 2 ( l + b )

                                         = 2 ( 12 + 16 )

                                         = 2 ( 28 )

                                         = 56 cm

Therefore, perimeter = 56 cm.

Answer = c ) 56 cm

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