A triangle with one angle that is 90 degrees and the other two angles are less than 90 degrees. A obtuse b acute c equilateral d right

Since there is a 90 degree angle this makes a right triangle.

an obtuse has one angle over 90

an acute is smaller than 90

an equilateral has all the numbers the same

However, the answer is D a right triangle

Answer

A. 129.3

B. The students ages can be any number within the ranges, so having the middle number wont represent the other possible heights.

Step by step

'h' is the number between the surrounding number, the first would be 122.

You need to multiply the hight by frequency of each one,

122x7 =854

126x8=1008

130x13=1690

134x9=1206

138x3=414

Add them up = 5172

5172/40 =129.3