Question

A triangle has side lengths of 3x,4x and 5x. If the area of the triangle is 121.5cm2, use any appropriate method to determine the value of x.

Answer 1

Answer:

the answer of your question is 10.125

Answer 2

Answer:

40 cm

Step-by-step explanation:

Area of a right angled triangle

=21×b×h

⇒60=21×(5x)×(3x−1)

⇒24=x(3x−1)

⇒3x2−x−24=0

⇒3x2−9x+8x−24=0

⇒3x(x−3)+8(x−3)=0

∴x=−38, 3

For x=3, AB=3(3)−1=9−1=8

BC=5×3=15

AB2+BC2=AC2

⇒AC2=82+152=64+225=289

∴AC=17 units(cm)

∴ perimeter =AB+BC+CA

=8+15+17=40cm.

hope it helped.