Question

In triangle ΔABC, AB = 8cm, BC = 15cm then find CA
​

Answer 1

Answer:

17 cm

Step-by-step explanation:

According to Pythagoras theorem,

CA² = AB² + BC²

⇒ CA² = 8² + 15² = 64 + 225 = 289 cm

⇒ CA = √289 = 17 cm

Answer 2

Using Pythagoras theorem in △ABC

(AB)  

2

+(BC)  

2

=(AC)  

2

 

(15)  

2

+(8)  

2

=(AC)  

2

 

⇒(AC)  

2

=225+64=289

⇒AC=17cm

Now inradius r=  

s

Δ

​

 

where Δ is the area of triangle and s is semi perimeter.

Δ=  

2

1

​

×8×15=60

s=  

2

8+15+17

​

=  

2

40

​

=20

⇒r=  

s

Δ

​

=  

20

60

​

=3cm