MCQ in Plane Trigonometry Part 3 – Answer Key | ECE Board Exam

This is the answer key for Part 3  the final set of the Plane Trigonometry MCQ Series on Pinoybix.

If you’ve made it through all three parts, that’s a solid block of review behind you. But finishing the questions is only half the work. This is where you go back, check every answer, and make sure you actually understand the solution and not just the result.

The answers compiled here come from past ECE Board Exam problems, engineering mathematics books, academic journals, and trusted references in the field. They reflect the kind of problems that appear in the Engineering Mathematics section of the board exam, and working through them carefully gives you a clearer picture of where you stand.

By the time you’re reviewing Part 3, you should be identifying patterns and the way certain question types are framed, the formulas that keep coming up, the common traps that throw people off. If you’re still seeing surprises here, that’s useful information. It means there’s still work to do before exam day.

Go through every item. Own your mistakes. That’s what this is for.

Good luck on your board exam. You’ve put in the work and make sure it shows.

101. B. 16 cm

Solution: Find the length of the shortest leg if it is 14 cm shorter than the other leg

102. C. 47.9

Solution: how far directly from M, in km. will be it after 2 hours?

103. A. 5.144 cm

Solution: Find the third side of a triangle

104. B. 27

Solution: Given a triangle: C = 100°, a = 15, b = 20. Find c

105. C. 14.63 units

Solution: Solve for side “a” of the triangle

106. B. 27

Solution: In a triangle, find the side c if the angle C = 100°, side b = 20, and side a = 1

107. B. 93.74

Solution: What is the interior angle (in degrees) opposite the longest side?

108. C. 4.73 cm

Solution: Determine the distance from the point of intersection of the angular bisectors to side AB

109. D. 14.3

Solution: Find the point of intersection of the angular bisector from the vertex C

110. C. 36.3 meters

Solution: What is the length of the median drawn from vertex A to side BC?

111. C. 52.43

Solution: The length of the longest side is

112. A. 21.74 cm

Solution: Find the length of the bisector of angle C

113. C. 125 meters

Solution: The length of this dividing line is:

114. C. 19.94

Solution: Find the dimension of the triangle

115. B. 274 meters

Solution: Approximate the shortest distance of tower C to the highway

116. C. after 2.13 hours

Solution: If the wireless communication range of the airplane is 700 miles, when will it lose contact with the carrier?

117. B. 2√5 meters

Solution: How far is the observer from the statue?

118. C. 100 (√30) / 3

Solution: Solution: Find the distance AB

119. D. 8.09 meters

Solution: Find the height of the tree

120. B. 12493

Solution: The height of the mountain in feet is

121. B. 11 meters

Solution: Find the height of the pole

122. B. 54.23 meters

Solution: What is the length of the pole?

123. D. 92.54 feet

Solution: What is the height of the tower?

124. D. 40.7

Solution: If the height of tower B is 120 m, how high is tower A in m?

125. C. 259.2

Solution: How far is A from the building in m?

126. B. 73.61 meters

Solution: What is the height of the tower?

127. A. 47.1 meters

Solution: How high is C from the horizontal line through A?

128. C. P601,650.00

Solution: If the land cost P1,500.00 per square meter, the cost of the roadway is

129. A. 0.5 m²

Solution: What would be the area of the shadow on the ground

130. C. 8√2 cm

Solution: Find the vertical distance between the lower corner and the upper corner

131. A. 9.17 inches

Solution: Find the distance between the tips of the hands at 5:40 AM

132. A. N 40° E

Solution: If the bearing of A from B is 40° W, then the bearing of B from A is

133. C. 15.56°

Solution: Find the angle between the directions of the two paths

134. C. 3.732 km

Solution: Find the shortest distance from one road to a gas station

135. C. 4.73 cm

Solution: Find the distance from the point of intersection of the angle bisectors

136. A. 24 m

Solution: At what distance from the base of the house will the antenna and the house subtend equal angle?

137. C. 19.36 m

Solution: Find the height of the building

138. B. 230.94 meters

Solution: Find the distance between the two towers

139. C. 10.2 m

Solution: How tall is the pole?

140. D. 6.71 miles

Solution: How far apart are the two towns?

141. C. 45.54 feet

Solution: Find the length of the shortest ladder

142. A. 81.6 feet wide

Solution: If the ladder is 50 ft. long, how wide is the street?

143. B. 358.49 feet

Solution: Find the height of the hill if the height of tower is 116 feet

144. D. 252.8 meters

Solution: What is the width of the river?

145. C. 230.94 m

Solution: How far apart are the two towers?

146. A. 3,200 km

Solution: Find the radius of the 60th parallel of latitude

147. B. 90.35 m

Solution: How high is the taller tower?

148. D. 74.16 m

Solution: Find the height of the light house

149. C. 30°

Solution: If the complement of an angle theta is 2/5 of its supplement

150. C. 16.58

Solution: Find the height of a lamp post if the angle of elevation changes

Online Questions and Answers in Plane Trigonometry Series

Following is the list of multiple choice questions in this brand new series:

Online Questions and Answers in Spherical Trigonometry

Mathematics Board Examination Mastery | Math Engineering Pre-Board