An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.

The surface area of a cube is (2 x length x width) + (2 x width x height) + (2 x length x height):

sa = 2lw + 2wh + 2lh
sa = (2 x 8 x 4) + (2 x 4 x 1) + (2 x 8 x 1)
sa = (64) + (8) + (16)
sa = 88

To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

4a - 3a = 1a

An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite:

d° = b° + c°

To find angle c, remember that the sum of the interior angles of a triangle is 180°:

180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 37° - 40° = 103°

So, d° = 40° + 103° = 143°

A shortcut to get this answer is to remember that angles around a line add up to 180°:

a° + d° = 180°
d° = 180° - a°
d° = 180° - 37° = 143°

To solve this equation, isolate the variable for which you are solving (a) on one side of the equation and put everything else on the other side.

9a + x = 2a + x + 4
9a = 2a + x + 4 - x
9a - 2a = x + 4 - x
7a = + 4
a = \( \frac{ + 4}{7} \)
a = \( \frac{}{7} \) + \( \frac{4}{7} \)
a = x + \(\frac{4}{7}\)