Question

△BCE∼△JKL
. If m∠B=89°
, m∠C=13°
, and m∠E=78°
what is m∠J
?(1 point)
m∠J=

°

1 answer

Since triangles \( \triangle BCE \) and \( \triangle JKL \) are similar (denoted as \( \triangle BCE \sim \triangle JKL \)), it follows that corresponding angles are equal.

Given:

  • \( m\angle B = 89^\circ \)
  • \( m\angle C = 13^\circ \)
  • \( m\angle E = 78^\circ \)

From the properties of triangles, we know that the sum of angles in a triangle is \( 180^\circ \): \[ m\angle B + m\angle C + m\angle E = 180^\circ \]

Let's confirm this: \[ 89^\circ + 13^\circ + 78^\circ = 180^\circ \] This is correct.

Now, in similar triangles, \( \angle B \) corresponds to \( \angle J \). Therefore, we have: \[ m\angle J = m\angle B = 89^\circ \]

Thus, the measure of angle \( J \) is: \[ \boxed{89^\circ} \]