The diagram shows some land in the shape of a quadrilateral ABCD. AB = 6 km, AD = 5 km and CD = 12 km Angle BAC = 30 The land is sold for £10 million per square kilometre. Calculate the total cost of the land.
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Answer:
£495 million
Step-by-step explanation:
To find out the total cost of the land, we need to first calculate the area of the land.
Step 1: Find area of right angled triangle ADC
AD = 5 km,
DC = 12 km
Area of the right triangle = ½*a*b
a = 5km
b = 12km
Area = ½*5*12
= 5*6
Area of ADC = 30 km²
Step 2: Find the area of triangle ABC
First, let's find the length of AC using Pythagorean theorem
AC² = AD² + DC²
AC² = 5² + 12² = 25 + 144
AC = √169
AC = 13km
Area of ∆ABC = ½*AB*AC*sin(30°)
= ½*6*13*0.5
= 3*13*0.5
Area of ∆ABC = 19.5 km²
Total area of the land = area of ∆ADC + ∆ABC = 30 + 19.5 = 49.5 km²
Step 3: calculate how much the land costs
If the land costs £10 million per km²,
Cost of 49.5 km² = 49.5 × 10 = £495 million