Question

Three angles of a quadrilateral are 75,120, 90,then the fourth angle..​

Answer 1

75

General Formulas and Concepts:

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

Geometry

• Sum of Angles in a Quadrilateral: 360

Explanation:

Step 1: Set up

75 + 120 + 90 + ∠4 = 360

Step 2: Solve

1. Add: 285 + ∠4 = 360
2. [Subtraction Property of Equality] Subtract 285 on both sides: ∠4 = 75