The area of the triangle ABD is 56cm2. Work out the length of CD

Answer:
8.2
Step-by-step explanation:
Area of triangle is calculated by multiplying height to the base and that divided by two
20 × h ÷ 2 = 56^2
h = 5.6
The square length of CD is equal to sum of square length of height and base
6^2 + 5.6^2 = CD^2
CD = 8.2