- A60°
- B30°
- C45°
- D120°
Step-by-Step Solution
Let angle = , complement . Equation: → → → °.
Answer: A) 60°
An angle is twice its complement. Find the angle.
Class 7Lines and AnglesLines and Angles
Key idea: Solving 'find the angle' problems
Most Class-7 angle problems give you one or two angle measures and ask you to find an unknown one. The recipe:
1. Identify the relationship: vertically opposite? linear pair? corresponding? alternate?
2. Write an equation: equal-to or sum-to-180.
3. Solve for the unknown.
4. Mark it back on the diagram and sanity-check (acute should look acute, obtuse should look obtuse).
1. Identify the relationship: vertically opposite? linear pair? corresponding? alternate?
2. Write an equation: equal-to or sum-to-180.
3. Solve for the unknown.
4. Mark it back on the diagram and sanity-check (acute should look acute, obtuse should look obtuse).
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More Class 7 Lines and Angles practice
Two angles whose measures add up to exactly 90° are called what?Which of the following best describes a transversal?Can two acute angles be supplementary to each other?Can two obtuse angles be supplementary to each other?Two complementary angles are in the ratio 2 : 3. Find the smaller angle (in degrees).