m∠A = 42 and m∠C = 57. Find m∠B.A. 81 B. 99 C. 132 D. 147

1 answer:

5 0

A.
because the total distance of every triangle 180. Add the two other angles so 42+ 57 =99. Then you have to subtract those two combined angles to find the missing one from the total distance, which is 180. 180-99=81. the answer is A. 81

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Find the midpoint of the segment with the following endpoints. (2,9) and (8,1)

vazorg [7]

Answer:

$\displaystyle (5,5)$

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Algebra I

Coordinates (x, y)
Midpoint Formula: $\displaystyle (\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})$

Step-by-step explanation:

Step 1: Define

Point (2, 9)

Point (8, 1)

Step 2: Identify

(2, 9) → x₁ = 2, y₁ = 9

(8, 1) → x₂ = 8, y₂ = 1

Step 3: Find Midpoint

Simply plug in your coordinates into the midpoint formula to find midpoint

Substitute in points [Midpoint Formula]: $\displaystyle (\frac{2+8}{2},\frac{9+1}{2})$
[Fractions] Add: $\displaystyle (\frac{10}{2},\frac{10}{2})$
[Fractions] Divide: $\displaystyle (5,5)$