Question

A triangle of area 80 sq. cms has two of its sides as 12 cms and 16 cms. If the inradius of
the triangle is 4 cms, then find the circumradius.
A.7.5cm
B.8cm
C..7.2cm
D.7.8cm
​

Answer 1

Answer:

the circumradius. = 7.2cm

Step-by-step explanation:

A = Area of Traingle =  s * r  = 80 cm²

r = inradius = 4 cm

s = semiperimeter  = (12 + 16 + c)/2

c is third side of triangle

=> 80 = 4  * ( 12 + 16 + c) / 2

=> 40 = 28 + c

=> c = 12

Third side = 12 cm

R = Circumradius

R = abc/4A

=> R = 12 * 16 * 12 / (4 * 80)

=> R = 7.2

the circumradius. = 7.2cm

option C