2D Area & Perimeter: WJEC GCSE Intermediate June 2019 Unit 1 Q8

Intermediate June 2019 Unit 1 Q8

WJECIntermediateCurrent spec6 marks2D Area & Perimeter

8. In this question, you will be assessed on the quality of your organisation, communication and accuracy in writing.

In the diagram below, ABCE is a square and CDE is a right-angled triangle.
The length of DE is 4 cm and the area of triangle CDE is 14 cm².

Calculate the area of the whole shape ABCDE.
You must show all your working. [4 + 2 OCW]

Diagram not drawn to scale

Mark scheme

Scheme	Marks	Comments
(Area of the triangle CDE =) \(14 = \dfrac{4 \times \text{CE}}{2}\)	M1	Lengths may be shown on the diagram. Accept equivalent e.g. 28 = 4 × CE.
(CE =) 7 (cm)	A1
(Area ABCE = 7 × 7 =) 49 (cm²)	B1	FT ‘their stated or shown length CE’.
(Area of whole shape = 49 + 14 =) 63 (cm²)	B1	FT ‘their stated or shown area of square’ + 14.
Organisation and Communication.	OC1	For OC1, candidates will be expected to: present their response in a structured way explain to the reader what they are doing at each step of their response lay out their explanation and working in a way that is clear and logical write a conclusion that draws together their results and explains what their answer means
Accuracy of writing.	W1	For W1, candidates will be expected to: show all their working make few, if any, errors in spelling, punctuation and grammar use correct mathematical form in their working use appropriate terminology, units, etc

Scheme	Marks	Comments
(Area of the triangle CDE =) \(14 = \dfrac{4 \times \text{CE}}{2}\)	M1	Lengths may be shown on the diagram.
(CE =) 7 (cm)	A1
(Area Trapezium ABCD = ) \(\dfrac{[(7 + 4) + 7] \times 7}{2}\)	M1	FT ‘their stated or shown length CE (=CB)’ consistently as ‘their 7’.
= 63 (cm²)	A1

(The alternative method is printed in italics in the original. The OC1 and W1 rows are printed after the alternative method in the original.)