Question

ABC and ACD are both right-angled triangles.

D
a)
Explain why the length of AC
is 13 cm.
5 cm
C
5 cm
b)
Calculate the length of AD.
Give your answer correct
to 1 decimal place.
B
A
12 cm

Answer 1

In the picture attached, the question is shown.

a) Applying Pythagorean theorem to triangle ABC, and solving for AC:

CB² + BA² = AC²

5² + 12² = AC²

√169 = AC

13 cm = AC

b) Applying Pythagorean theorem to triangle ACD, and solving for AD:

CD² + AC² = AD²

5² + 13² = AD²

√194 = AD

13.9 cm = AD