Foundation June 2018 Unit 1 Q17
17. In the diagram below, ABCE is a square whose perimeter is 28 cm.
CDE is a right-angled triangle whose area is 35 cm2.
Diagram not drawn to scale
Calculate the length of DE.
You must show all your working. [4]
| Scheme | Marks | Comments |
|---|---|---|
| (EC = Side of the square =) \(\dfrac{28}{4}\) | M1 | Lengths may be seen on the diagram. |
| = 7(cm) | A1 | Any side of square shown as 7(cm) is M1A1. |
| (Area of triangle CDE =) \(\dfrac{7 \times \text{DE}}{2}\) = 35(cm2) | M1 | FT ‘their stated or shown length for EC’. |
| (DE =) 10(cm) | A1 |