ACT Preparation / Unit 14 ACT 1320 short lesson, about 20 seconds
Solving Right Triangles
Captions available
The idea
To find an angle from two sides, use an inverse trig function: if sin A = 0.5, then A = sin⁻¹(0.5) = 30°. The two acute angles add to 90°.
In practice
Legs 7 and 7√3 give tan A = 7/(7√3) = 1/√3, so A = 30° and the other angle is 60°.
Where people slip
sin⁻¹ gives an angle; it is not 1 over sine.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
Unlocks
- Nothing yet depends on this.
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