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(1) Since it is an equilateral triangle, the angle is 60 degrees.

It is acute, equiangular, isosceles, and equilateral.

(2) 50+2x=180, 2x=130, x=65 degrees.

Acute and isosceles.

No problem! I am always happy to help!

But, shouldn't you divide 23.4 by 2.20?

1st one: Base, which is a rectangle: 18*20=360mi^2

2*(1/2*20*14.2) and 2*(1/2*18*14.9)=20*14.2+18*14.9=284+268.2=552.2mi^2

So, 360mi^2+552.2mi^2=912.2mi^2.

5th one: Two trapezoids! No! Area of a trapezoid: 2(51.85)- use the formula=103.7 mi^2.

Rectangles: 2(14*7)=196 mi^2

Bottom rectangle: 5*14=70 mi^2

Top rectangle: 168 mi^2

So, 103.7+196+70+168=537.7? I might be wrong.

Last one: There are 6 faces, I think, wait, yes! So, the area of the first face, 2nd face: 2(20*10)=2(200)=400yd^2

Area of the 3rd face, 4th face: 2(20*20)=2(400)=800yd^2

Ares of the 5th face, and 6th face: 2(20*10)=2*200=400yd^2.

Thus, the surafce area is 400+400+800=1600yd^2. You're correct!

GCF common factor is the way to solve it! The GCF is 6, because it's the greatest number that evenly divided 12,24, and 30.

Thank you, CPhill! 

x+5y=-15, y=1/5x+1. First, rearrange, then we can multiply the second equation by 5, and let the first equation be.

x+5y=-15   x-5y=-5

Now, we can subtract! 5y--5y=-15--5, 10y=-10, so y=-1.

We can plug the value of y in the first equation, in order to solve for x.

x+5(-1)=-15, x+-5=-15, x-5=-15, x=-10.

Thus, the answer is (-10,-1).

What happens if you multiply the first equation by -3 and the second equation by 2? Let's try it!

If we follow what I said, we will get: 6x+-18y=114 and 6x-8y=64. Now, we can subtract, to attain -10y=50, so y=-5. We can plug the value of y back in the second equation, to get: 3x-4(-5)=32, 3x+20=32, 3x=12, x=4. Thus, the answer is : (4,-5).