Question

construction the diagram shows an example of the pratt truss used in bridge construction. find m∠1. 145° need help?

Explanation:

Step1: Identify adjacent supplementary angle

The angle of \(145^\circ\) and its adjacent angle (forming a linear pair) sum to \(180^\circ\). Let the adjacent angle be \(x\), so \(x + 145^\circ=180^\circ\), then \(x = 180^\circ - 145^\circ = 35^\circ\).

Step2: Use right triangle angle sum

In the right triangle (with the right angle), the sum of angles is \(180^\circ\). Let \(m\angle1\) be the angle we need. We know one angle is \(90^\circ\) and another is \(35^\circ\) (from Step 1). So \(m\angle1+90^\circ + 35^\circ=180^\circ\), then \(m\angle1=180^\circ - 90^\circ - 35^\circ = 55^\circ\).

Answer:

\(55^\circ\)