According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:

c² = a² + b²
c² = 5² + 3²
c² = 25 + 9
c² = 34
c = \( \sqrt{34} \)

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° - 21° - 61° = 98°

So, d° = 61° + 98° = 159°

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° - 21° = 159°

To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

6a x 3b = (6 x 3) (a x b) = 18ab

The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:

c² + 7c + 10 = 0
(c + 2)(c + 5) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (c + 2) or (c + 5) must equal zero:

If (c + 2) = 0, c must equal -2
If (c + 5) = 0, c must equal -5

So the solution is that c = -2 or -5

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.