Waste less time on Facebook — follow Brilliant.

Congruent and Similar Triangles

Congruent and Similar Triangles: Level 1 Challenges


In triangles \(ABC \) and \(DEF\), if we know that \( AB = EF, BC = DE \) and \( \angle ABC = \angle DEF \), are the triangles congruent?

In the above diagram, \(x=21,\) \(y=14,\) \(\alpha={35}^\circ,\) and \(\beta={75}^\circ.\) Which condition would mean that the two triangles are similar?

Note: The above diagram is not drawn to scale.

In the adjoining figure, \(XY\) is parallel to \(AC\). If \(XY\) divides the triangle into two halves with equal area, compute \(\dfrac{AX}{AB} \).

Did you know you can approximate the diameter of the moon with a coin \((\)of diameter \(d)\) placed a distance \(r\) in front of your eye?

If the distance between the moon and your eye is \(R,\) what is the diameter of the moon?

Triangle \(\triangle ABC\) is similar to \(\triangle DEF\), and the ratio of their areas is \(9:25.\) If the length of \(\overline{DE} \) is \(60,\) what is the length of \(\overline{AB} \)?


Problem Loading...

Note Loading...

Set Loading...