Answer:
B.17.5cm²
Step-by-step explanation:
S=a+b+c/2=
5+8+7/2=10
S=10
Area of the triangle=[tex]\sqrt{3(5-a)(5-b)(5-c)}[/tex]
⇒[tex]\sqrt{10(10-5)(10-8)(10-7)}[/tex]
⇒[tex]\sqrt{10*5*2*3}[/tex]
⇒[tex]\sqrt{300}[/tex]
⇒17.5cm²
hope it helps...
have a great day!!
