Question

In the diagram, m < ACB = 65. m < ECD = A. 180 B. 115 C. 65 D. 90

Answer 1

`\angle ECD = 115`

Explanation:

Given

`\angle ACB = 65`

Required

Determine
`\angle ECD`

From the attached image, we have:

`\angle ACB +\angle ECD = 180` ---- angle on a straight line

This gives:

`65 +\angle ECD = 180`

Subtract 65 from both sides

`\angle ECD = 180 - 65`

`\angle ECD = 115`