Answer:
80°=x°[by alternate exterior angle]
A(base)=6*6=36
A( triangle)=1/2*(base of the triangle)*height( of the triangle)=1/2*6*4=12
one base +4 triangles=36+4*12=36+48 =84 cm²
Hello! Let's work this problem from left to right to make things a bit easier ;)
6.5+(-2) is the same as 6.5-2, since adding a negative is the same as subtracting a positive. 6.5-2=4.5
Now, we have to add 10.5 to 4.5, which gives us the grand total of 15. I hope this helped! Let me know if you need anything else!