Question

In the given figure, find the length AC.
B
17 cm
10 cm
8 cm
A
D​

Answer 1

Answer:

In ∆ABC, ∠B = 90° , and l(BC) = 21, and l(AB) = 20

∴ According to Pythagoras’ theorem,

∴ l(AC)2 = l(BC)2 + l(AB)2

∴ l(AC)2 = 212 + 202

∴ l(AC)2 = 441 + 400

∴ l(AC)2 = 841

∴ l(AC)2 = 292

∴ l(AC) = 29

Perimeter of ∆ABC = l(AB) + l(BC) + l(AC)

= 20 + 21 + 29

= 70

∴ The length of hypotenuse AC is 29 units, and the perimeter of ∆ABC is 70 units.