Please someone help me with 11 and 12

11: n=1.5

Step-by-step explanation:

11: First we must set the problem up Which would be n*4n*40 divide it all by 2 because it is a triangle.

Since we have to find the sum which would be 180 we now have to find the number

We now have n*4n*40/2=180

So if we start to plug in n which would be 1.5 because 2 and 1 both don't work but they are over and under the number.

So therefore when you plug in the numbers 1.5*(4*1.5)*40/2=180

1.5*6*40/2  |   9*40/2   |   360/2   |   180=180

Therefore your answer is n=1.5

For 12 I am not sure I tried but I didn't really make sense to me either but I can guarantee that 11 is correct.

mark branliest

step-by-step explanation:

.6 is 1/2 of 12

the answer is actually d. i just took the test