Q. 54.1( 15 Votes )

# A field is in the shape of a trapezium having parallel sides 90 m and 30 m. These sides meet the third side at right angles. The length of the fourth side is 100 m. If it costs Rs 4 to plough 1m2 of the field, find the total cost of ploughing the field.

Answer :

PQ = 90m

RS = 30m

QR = 100m

PQ = PT + TQ = 90m

⇒ 30 + TQ = 90

⇒ TQ = 60

In ΔTRQ,

QR^{2} = TR^{2} + QT^{2}

⇒ 100^{2} = TR^{2} + 60^{2}

⇒ TR^{2} = 10000-3600

⇒ TR^{2} = 6400

⇒ TR = 80m

Area (PQRS) =

Area(PQRS) =

Area(PQRS) = 60 × 80 = 4800 m^{2}

Cost of ploughing = Area(PQRS) × Cost per m^{2}

∴ Cost of ploughing = 4800 × 4 = Rs. 19200.

Rate this question :

A piece of land is in the shape of a rhombus ABCD in which each side measures 100m and diagonal AC is 160m long. Find the area of the rhombus.

RS Aggarwal & V Aggarwal - Mathematics

The question consists of two statements namely, Assertion (a) and Reason (R). Please select the correct answer.

The perimeter of an isosceles triangle is 32cm. The ratio of one of the equal side to its base is 3: 2. Find the area of the triangle.

RS Aggarwal & V Aggarwal - Mathematics