Answer:
b)480 cm^2
Step-by-step explanation:
perimeter=(16+12+20) cm
=48 cm
lateral surface area= perimeter × height
=48×10 =480 cm^2
Two or more angles whose sum is 180° are called supplementary angles. The measure of the ∠y is 120°.
<h3>What are supplementary angles?</h3>
Two or more angles whose sum is 180° are called supplementary angles. If a straight line is intersected by a line, then there are two angles form on each of the sides of the considered straight line. Those two-two angles are two pairs of supplementary angles. That means, that if supplementary angles are aligned adjacent to each other, their exterior sides will make a straight line.
Given the puck strikes the wall at an angle of 30°, it goes away at the same angle of 30°. Therefore, the measure of angle y can be found using the sum of the angle as a supplementary angle. Thus, we can write,
30° + ∠y + 30° = 180°
60° + ∠y = 180°
∠y = 180° - 60° = 120°
Hence, the measure of the ∠y is 120°.
Learn more about Supplementary Angles:
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54° × π/180 = 0.9425radians
