Answer:
90°; 55°; 35°; 110°; 70°
Step-by-step explanation:
A rectangle has corner angles that are 90°. When the corner angle is divided into two parts, the total of the parts is 90°.
Each of the triangles is isosceles. The figure is symmetrical about its center.
An exterior angle to a triangle is equal to the sum of the remote interior angles.
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∠SRT = 90° . . . . a corner angle
∠STR = 55° . . . . symmetrical to the given angle
∠QRS = 180° -55° -90° = 35° . . . . sum of angles in ΔQRS is 180°
∠QPT = 2×55° = 110° . . . . exterior angle to ΔQPS; ∠QSP =∠SQP
∠TPR = 180° -110° = 70° . . . . forms a linear pair with ∠QPT
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There are numerous ways to figure any or all of these angles. They come down to the fundamentals: angles in a triangle total 180°; angles that form a line total 180°; corner angles of a rectangle are 90°. Base angles of an isosceles triangle are congruent.
The exterior angle rule derives from the sum of angles in a triangle and on a line both being 180°.
