Posted by **bob** on Friday, February 3, 2012 at 7:28pm.

ABCD is a trapezoid with DC parallel to AB, AB=4, AD=4, angle A=60, angle C=45. Find DC and BC

- geometry -
**Reiny**, Friday, February 3, 2012 at 8:38pm
Make a sketch, marking all the given data

join BD

since AB = AD = 4, the triangle is isosceles, furthermore it is easy to see that it must be equilateral, all angles are 60° and BD = 4

By alternate angles , angle BDC = 60° leaving angle CBD = 75°

Using the sine law,

BC/sin60 = 4/sin45

BC = 4sin60/sin45 = 4.8989 or appr. 4.9

find DC in the same way

- Maths -
**Rohit**, Friday, February 3, 2012 at 10:01pm
Find the radius of a right circular cyilender whose volume is 3080cu.cm and height is 20cm.

- geometry -
**Anonymous**, Saturday, February 4, 2012 at 12:45am
v = pi r^2 h

3080 = pi * 20 * r^2

r^2 = 3080/20pi

r = ...

- geometry -
**rakib**, Monday, February 6, 2012 at 11:20am
The two triangles above are similar. If XZ = 10 cm, YZ = 15 cm, and AC = 18 cm, what is the length of BC?

## Answer This Question

## Related Questions

- Geometry - I have four questions: 1. The area of trapezoid ABCD is 60. One base ...
- Geometry - ABCD is an isosceles trapezoid. Angle CDA = 80. Find the measure of ...
- geometry - Suppose ABCD is a trapezium in which AB is parallel to CD and AD=BC....
- GEOMETRY - ABCD is a cyclic trapezium whose sides AD and BC are parallel to each...
- geometry - ABCD is a trapezoid with AB parallel to DC. If AB=25, BC=24, CD=50 ...
- calculus - a trapezoid is a quadrilateral with (only) two sides (called bases) ...
- Geometry - ABCD is a trapezoid with AB < CD and AB parallel to CD. \Gamma is ...
- GEOmetry!!..... - ABCD is a trapezoid with AB<CD and AB parallel to CD. Γ...
- Math repost - trapezium ABCD, with AB and DC being parallel, with diagonal ...
- MATH - ABCD is a quadrilateral in which AB parallel DC and AD=BC.prove that (1)...

More Related Questions