Given a circle with circumference and a central angle of radians, what is the length of the arc subtended by the angle ?
Table of contents
- 0. Review of College Algebra4h 43m
- 1. Measuring Angles40m
- 2. Trigonometric Functions on Right Triangles2h 5m
- 3. Unit Circle1h 19m
- 4. Graphing Trigonometric Functions1h 19m
- 5. Inverse Trigonometric Functions and Basic Trigonometric Equations1h 41m
- 6. Trigonometric Identities and More Equations2h 34m
- 7. Non-Right Triangles1h 38m
- 8. Vectors2h 25m
- 9. Polar Equations2h 5m
- 10. Parametric Equations1h 6m
- 11. Graphing Complex Numbers1h 7m
2. Trigonometric Functions on Right Triangles
Trigonometric Functions on Right Triangles
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Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
In a right triangle, if two triangles have their corresponding acute angles equal, which angles are congruent to each other?
A
All three angles in both triangles are congruent.
B
No angles are congruent.
C
The corresponding acute angles in both triangles are congruent.
D
Only the right angles are congruent.
Verified step by step guidance1
Recall that in a right triangle, one angle is always 90° (the right angle), and the other two angles are acute angles whose measures add up to 90°.
If two right triangles have their corresponding acute angles equal, it means the two acute angles in one triangle match the two acute angles in the other triangle respectively.
Since the sum of the angles in any triangle is 180°, and the right angle is fixed at 90°, the remaining two angles must be complementary (add up to 90°).
Therefore, if the corresponding acute angles are equal, the right angles in both triangles are also equal (both 90°), making the triangles similar by the Angle-Angle (AA) similarity criterion.
Hence, the congruent angles between the two triangles are the corresponding acute angles and the right angles, but the problem specifically highlights the corresponding acute angles as congruent.
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