Answers

2016-01-23T17:37:18+05:30
123cm² will be the answer.
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2016-01-23T17:41:26+05:30
We have ,
AB II DC
AB = 18 cm
∠B = ∠C = 90°
CD = 12 cm
AD = 10 cm

Now from ∠B we will draw a line which will be parallel to AD and equals to AD
. This line will intersect CD at E.

We have a parallelogram with ED = 12 cm.

CE = 6cm

Now we have an ΔBCE

using Pythagoras theorem,
BE²= BC² + CE²
10 ² = BC² + 6²
100 - 36 = BC ²
64 = BC²
√64 = BC
8 = BC

so we have the height of the trapezium = 8 cm

Now area of trapezium = 1/2 × (base 1 + base2) × h
                                      = 1/2 ×(12 + 18 ) × 8
                                      = 120 cm²

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