ABCD is a trapezium - Edexcel - GCSE Maths - Question 7 - 2017 - Paper 2
Question 7
ABCD is a trapezium.
Work out the size of angle CDA.
Give your answer correct to 1 decimal place.
Worked Solution & Example Answer:ABCD is a trapezium - Edexcel - GCSE Maths - Question 7 - 2017 - Paper 2
Step 1
Using Pythagoras' Theorem
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Answer
To find the third side of triangle ABD, we can apply Pythagoras' theorem. The height from B to AD is 6 cm, and the base from A to B is 10 cm. Hence, the length of AB can be calculated as:
AB=(7.5)2+(10)2
Calculating gives:
AB=56.25+100=156.25=12.5 cm
Step 2
Finding Base Length of Triangle CDA
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Answer
To find the base length of triangle CDA, we know the total length AD is 24 cm. Subtracting the length of AB:
CD=24−10=14 cm
Step 3
Using Trigonometry to Find Angle CDA
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Answer
Now we can apply trigonometry to find angle CDA using the tangent function:
tan(CDA)=adjacentopposite=146
Calculating gives:
CDA=tan−1(146)
Using a calculator, we find:
CDA≈22.6∘
Rounded to 1 decimal place, the final answer is: