Area Problems The diagonal of a rectangle is √41 cm and its area is 20 sq. cm. The perimeter of the rectangle must be: 41 cm 9 cm 18 cm 20 cm 41 cm 9 cm 18 cm 20 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP √l2 + b2 = √41. Also, lb = 20. (l + b)2 = (l2 + b2) + 2lb = 41 + 40 = 81 ⟹ (l + b) = 9. ∴ Perimeter = 2(l + b) = 18 cm
Area Problems The base of right-angled triangle is 5 meters and hypotenuse is 13 meters . Its area will be? 25m2 30m2 None of these 28 m2 25m2 30m2 None of these 28 m2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Altitude = ?(13)2 - (5)2= ?144 = 12m ? Area of the triangle = (5 x 12 ) / 2 m2= 30m2
Area Problems A rectangular field is to be fenced on three sides leaving a side of 20 feet uncovered. If the area of the field is 680 sq. feet, how many feet of fencing will be required? 34 40 68 88 34 40 68 88 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP We have: l = 20 ft and lb = 680 sq. ft. So, b = 34 ft. ∴ Length of fencing = (l + 2b) = (20 + 68) ft = 88 ft
Area Problems The perimeter of an equilateral triangle is 90 cm. Find its area. 135?3 sq cm 151?3 sq cm 250?3 sq cm 225?3 sq cm 135?3 sq cm 151?3 sq cm 250?3 sq cm 225?3 sq cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Given that, perimeter = 90 cm? 3a = 90 cm [a = side]? a = 90/3 = 30 cm? Area = ?3a2 / 4 = ?3/4 x (30)2= 900 x ?3/4 = 225?3 sq cm
Area Problems The length of a rectangular field is 100 m and its breadth is 40 m. What will be the area of the field? (4 x 104) sq m (4 x 102) sq m (4 x 10) sq m (4 x 103) sq m (4 x 104) sq m (4 x 102) sq m (4 x 10) sq m (4 x 103) sq m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Required area = Length x Breadth= 100 x 40 = 4000 sq m= 4 x 103 sq m
Area Problems The area of sector of a circle of radius 5 cm, formed by an arc of length 3.5 cm is? 17.5 sq.cms 35 sq.cms 55 sq.cms 8. 75 sq.cms 17.5 sq.cms 35 sq.cms 55 sq.cms 8. 75 sq.cms ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of sector = ( arc length x radius ) / 2 cm2= (3.5 x 5 ) / 2= 8.75 cm2
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