Area Problems In a circle of radius 21 cm an arc subtends an angle of 72° at the centre. The length of the arc is? 21.6 cm 19.8 cm 26.4 cm 13.2 cm 21.6 cm 19.8 cm 26.4 cm 13.2 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Arc length = 2?r (?° / 360°) = 2 x (22/7) x 21 x (72° / 360°) cm= 26.4 cm
Area Problems The two parallel sides of a trapezium are 1 meters and 2 meters respectively . The perpendicular distance between them is 6 meters. The area of the trapezium is? 6 sq. meters . 12 sq. meters . 9 sq. meters . 18 sq. meters . 6 sq. meters . 12 sq. meters . 9 sq. meters . 18 sq. meters . ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of trapezium = 1/2 x sum of parallel sides x perpendicular distance between them= 1/2 (1 + 2) x 6 m2= 9 m2
Area Problems Four horses are be tethered at four concern of a square plot of side 63 meters, so that they just cannot reach one another. The area left ungrazed is? 785.8 m2 675.5 m2 780.6 m2 850.5 m2 785.8 m2 675.5 m2 780.6 m2 850.5 m2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area left ungrazed = [(63 x 63) - (4 x 1/4 x 22/7 x (63/2)2] m2= (63 x 63 - (99 x 63)/2 ) m2= 63 x (63 - 99/2) m2= 850.5 m2
Area Problems A triangle with three equal sides has its area equal to 3?3 sq cm . Find its perimeter . 7?3 cm 6?3 cm 2?3 cm 5?3 cm 7?3 cm 6?3 cm 2?3 cm 5?3 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP According to the question,?3a2/4 = 3?3 [ side = a, and area = ?3a2/4] ? a2/4 = 3 ? a2 = 3 x 4 ? a = 2?3? Required perimeter = 3a =3 x 2?3 = 6?3 cm
Area Problems If the side of a square is increased by 25%, then how much percent does its area get increased? 56.25 125 156.25 50 56.25 125 156.25 50 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let area 100 m2Then, side = 10 m New side = 125 % of 10= (125/100) x 10= 12.5 m New area = 12.5 x 12.5 m2=(12.5)2 sq. m? Increase in area = (12.5)2 - (10)2 m2= 22.5 x 2.5 m2=56.25 m2% Increase = 56.25 %
Area Problems What is the least number of squares tiles required to pave the floor of a room 15 m 17 cm long and 9 m 2 cm broad? 840 820 844 814 840 820 844 814 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Length of largest tile = H.C.F. of 1517 cm and 902 cm = 41 cm. Area of each tile = (41 x 41) cm2. ∴ Required number of tiles = ❨ 1517 x 902 ❩ = 814
EXAMIANS