Right triangle
In a right triangle, the sides and angles are connected. If you know two of them (at least one side), you can work out the rest with sine, cosine and tangent.
Your numbers
Answer
a
2.8008
b
4
c
4.8831
Angle A
35°
Angle B
55°
Angle C
90°
How to work it out
- 1a = b · tan A = 4 · tan 35° = 2.8008
- 2c = b / cos A = 4 / cos 35° = 4.8831
- 3B = 90° − A = 90° − 35° = 55°
The formula
sin A = a / c
The opposite leg divided by the hypotenuse.
cos A = b / c
The adjacent leg divided by the hypotenuse.
tan A = a / b
The opposite leg divided by the adjacent leg.
A + B = 90°
The two acute angles in a right triangle always add up to 90°.
More: Geometry
- PythagorasFind the missing side of a right triangle — with a drawing and working.
- Area and perimeterRectangle, triangle, parallelogram, trapezoid and circle — area and perimeter.
- Volume and surface areaBox, cube, cylinder, cone, sphere and pyramid — also in litres.
- The circleRadius, diameter, circumference and area from one known measurement — and sectors.
- AnglesThe third angle in a triangle and the angle sum of a polygon.
- Points in the coordinate systemDistance, midpoint and the line between two points — drawn in.