Answer: 31.5
Step-by-step explanation:
Fiest the formula of a triange is : b times h/2
B=3.5, H=18
3.5 times 18 divided by 2= 31.5
Since it aks for the area of only one triangle it will be 31.5!
I hope this helps and may God bless you! Have a nice day, bye!
