To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses:

(y + 6)(y + 2)
(y x y) + (y x 2) + (6 x y) + (6 x 2)
y² + 2y + 6y + 12
y² + 8y + 12

The area of a triangle is equal to ½ base x height:

a = ½bh
a = ½ x 1 x 8 = \( \frac{8}{2} \) = 4

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.

(5a)(4ab) - (2a²)(8b)
(5 x 4)(a x a x b) - (2 x 8)(a² x b)
(20)(a¹⁺¹ x b) - (16)(a²b)
20a²b - 16a²b
4a²b

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 circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)² : a = π r².