Chapter 6.5, Problem 7ST2

To determine

To find: whether given statement must be, may be, or cannot be true.

Answer to Problem 7ST2

The angle $\angle R$ cannot be an acute angle.

Explanation of Solution

Given information:

The longer diagonal of $▭QRST$ is $\overline{QS}$ ,

  $\angle R$ is an acute angle.

Calculation:

Consider the diagram below:

It is known that the quadrilateral $QRST$ is $\overline{QS}$

From the figure,

The angle $\angle R$ is above $90°$

Therefore, the angle $\angle R$ cannot be an acute angle.