Posted by **Maram** on Tuesday, April 19, 2011 at 12:10pm.

In triangle ABC ,if <A and <B are acute angles, and sin A=10/13 what is the value of cos A?

- Algebra 1 -
**Henry**, Thursday, April 21, 2011 at 3:31pm
sinA = 10/13.

This is assumed to be a rt triangle.

sinA = 10/13 = Y/r,

X^2+Y^2 = r^2,

X^2+(10)^2 = (13)^2,

x^2 = 169-100 = 69,

X = 8.3.

cosA = X/r = 8.3/13.

## Answer This Question

## Related Questions

- math - In triangle ABC ,if <A and <B are acute angles, and sin A=10/13 ...
- math - In triangle ABC if <A and <B are acute angles and sin 10/13 , what ...
- math - In triangle ABC if <A and <B are acute angles and sin 10/13 , what ...
- geometry - In triangle ABC, if <A and <B are acute angles, and sin A 10/13...
- maths - Choose three options which are true: a) an angle of 150 degrees is ...
- maths - Choose three options which are true: a) an angle of 150 degrees is ...
- ALGEBRA 1 - If x and 3x-10 represent the measure of the acute angles of a right ...
- Trigonometry - in triangle abc, if sin c= (sin a + sin b )/ ( cos a + cos b ) ...
- Geometry Please Help With One Multiple Choice - Write the ratios for sin A and ...
- Geometry One multiple choice question! - Write the ratios for sin A and cos A. {...

More Related Questions