Question

LE

11. The diagram shows two night-angled triangles, joined together along a common side
AB = 10-8 cm, BC = 14 4 om and CD = 24 cm.
24 am
10-8 cm
B
14-4 cm
Diagram noi drawn to scale
Calculate the area of triangle ACD.
You must show all your working.
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Answer 1

216 cm²

Explanation:

Area of ∆ACD = ½*CD*CA

CD = 24 cm

CA = ?

Use pythagorean theorem to find CA.

Thus:

CA² = AB² + BC²

Substitute

CA² = 10.8² + 14.4² = 324

CA = √324

CA = 18 cm

Area of ∆ACD = ½*CD*CA

Substitute

Area = ½*24*18

= 216 cm²