Question

Difficulty: EasyPerimeter and Area of Plane Shapes

A trapezium has parallel sides of length 12 cm12\text{ cm} and 18 cm18\text{ cm}, and a perpendicular height of 7 cm7\text{ cm}. What is the area of the trapezium?

  1. 105 cm2105\text{ cm}^2Answer
  2. B
    210 cm2210\text{ cm}^2
  3. C
    216 cm2216\text{ cm}^2
  4. D
    37 cm237\text{ cm}^2

Answer

The area of the trapezium is 105 cm2105\text{ cm}^2.
The area of a trapezium is calculated using the formula Area=12(a+b)h\text{Area} = \frac{1}{2}(a + b)h, where aa and bb are the lengths of the parallel sides, and hh is the perpendicular height. Substituting a=12 cma = 12\text{ cm}, b=18 cmb = 18\text{ cm}, and h=7 cmh = 7\text{ cm} yields Area=12(12+18)×7=12(30)×7=105 cm2\text{Area} = \frac{1}{2}(12 + 18) \times 7 = \frac{1}{2}(30) \times 7 = 105\text{ cm}^2.

Step-by-Step Solution

1
Identify the given dimensions of the trapezium
Parallel sides a=12 cma = 12\text{ cm}, b=18 cmb = 18\text{ cm}, and height h=7 cmh = 7\text{ cm}.
These are the necessary parameters for the area formula of a trapezium.
2
Sum the lengths of the parallel sides
a+b=12+18=30 cma + b = 12 + 18 = 30\text{ cm}.
The area formula requires the sum of the bases.
3
Multiply by the perpendicular height and divide by 2
\text{Area} = \frac{1}{2} \times 30 \times 7 = 15 \times 7 = 105\text{ cm}^2.
Applying the standard formula Area=12(a+b)h\text{Area} = \frac{1}{2}(a + b)h gives the plane region's total area.

Key Concept

Area of a Trapezium
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