3.) 3, 4, 5
&
4.) 6, 8, 10
Those two are right triangles because when you add the squares of the first two it should give you the square root of the third number
a^2 + b^2 = c^2
So
3^2 + 4^2 = 5^2
9 + 16 = 25
25 = 25
6^2 + 8^2 = 10^2
36 + 64 = 100
100 = 100
Therefore they are right triangles
But 1 & 2 aren’t right triangles because when you add the squares of the first two number, it doesn’t equal to the square root of the third number.
Hope this helps!!
Answer:
x=5,y=-2
Step-by-step explanation:
Surface area is just the area of all these 4 triangles plus the rectangle.
First we can find the area of the rectangle.

Half of the length is 28 cm, so the full length must be 28 * 2 = 56 cm.


The base for the left and right triangles are 27. The heights would be the net length minus half the length of the rectangle:

Calculate the area:



We have two of these triangles.

Now do the other two pair of triangles. The bases for them are 28 + 28 = 56 cm. The heights would be the net width minus the width of the rectangle:

Now find the area:



We have two of these triangles.

Add all the areas together: