Question

Find AB.
Round to the nearest tenth

Answer 1

AB ≈ 14.3

General Formulas and Concepts:

Math

Rounding

• If Z is < 5, then you round down
• If Z is ≥ 5, then you round up

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Equality Properties

• Multiplication Property of Equality
• Division Property of Equality
• Addition Property of Equality
• Subtraction Property of Equality

Pre-Calculus

• Law of Cosines: a² = b² + c² - 2(b)(c)cosA°

Explanation:

Step 1: Identify

a = x, b = 16, c = 5

A = 61°

Step 2: Solve for x

1. Substitute in variables [Law of Cosines]: x² = 16² + 5² - 2(16)(5)cos61°
2. Evaluate Exponents: x² = 256 + 25 - 2(16)(5)cos61°
3. Multiply: x² = 256 + 25 - 160cos61°
4. Evaluate Trig: x² = 256 + 25 - 160(0.48481)
5. Multiply: x² = 256 + 25 - 77.5695
6. Add: x² = 281 - 77.5695
7. Subtract: x² = 203.43
8. [Equality Property] Square root both sides: x = 14.2629
9. Round: x ≈ 14.3