Question

Triangle BCD is rotated 80° clockwise about the origin to form ΔKLM. If m∠KLM = 30°, what is m∠BCD? A. 110° B. 30° C. 80° D. 50°

Answer 1

It is still 30\textdegree, no matter how you turn it hope this helps.

Answer 2

The correct option is B.

Explanation:

Given information: Triangle BCD is rotated 80° clockwise about the origin to form ΔKLM and ∠KLM = 30°.

Rotation is a rigid transformation, it means the size and shape or image and preimage are same.

Triangle BCD is rotated 80° clockwise about the origin to form ΔKLM. It means both triangles are congruent.

`\triangle BCD\cong \triangle KLM`

The corresponding parts of congruent triangles are congruent, so

`\angle BCD\cong \angle KLM` (CPCTC)

`\angle BCD\cong 30^(\circ)`

`\angle BCD=30^(\circ)`

The measure of angle BCD is 30°. Therefore the correct option is B.